This is curious because it is always possible to clear the bios :

vince@Bob:~$ sudo flashrom -VE
flashrom v0.9.4-r1394 on Linux 3.0.0-15-generic (x86_64), built with libpci 3.1.7, GCC 4.6.1, little endian
flashrom is free software, get the source code at http://www.flashrom.org

Calibrating delay loop... OS timer resolution is 1 usecs, 730M loops per second, 10 myus = 11 us, 100 myus = 100 us, 1000 myus = 992 us, 10000 myus = 10064 us, 4 myus = 5 us, OK.
Initializing internal programmer
No coreboot table found.
DMI string system-manufacturer: "Acer"
DMI string system-product-name: "Aspire E380"
DMI string system-version: "R01-A2"
DMI string baseboard-manufacturer: "Acer"
DMI string baseboard-product-name: "EM61SM/EM61PM         "
DMI string baseboard-version: " "
DMI string chassis-type: "Desktop"
Found ITE Super I/O, ID 0x8726 on port 0x2e
Found chipset "NVIDIA MCP61" with PCI ID 10de:03e0.
This chipset is marked as untested. If you are using an up-to-date version
of flashrom please email a report to flashrom@flashrom.org including a
verbose (-V) log. Thank you!
Enabling flash write... This chipset is not really supported yet. Guesswork...
ISA/LPC bridge reg 0x8a contents: 0x00, bit 6 is 0, bit 5 is 0
Flash bus type is LPC
Found SMBus device 10de:03eb at 00:01:1
MCP SPI BAR is at 0xfec80000
Strange. MCP SPI BAR is valid, but chipset apparently doesn't have SPI enabled.
Please send the output of "flashrom -V" to flashrom@flashrom.org with
your board name: flashrom -V as the subject to help us finish support for your
chipset. Thanks.
OK.
This chipset supports the following protocols: LPC.
Super I/O ID 0x8726 is not on the list of flash capable controllers.
Probing for AMIC A49LF040A, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Probing for PMC Pm49FL002, 256 kB: probe_jedec_common: id1 0xbf, id2 0x50, id1 is normal flash content
Probing for PMC Pm49FL004, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Probing for SST SST49LF020, 256 kB: probe_jedec_common: id1 0xbf, id2 0x50, id1 is normal flash content
Probing for SST SST49LF020A, 256 kB: probe_jedec_common: id1 0xbf, id2 0x50, id1 is normal flash content
Probing for SST SST49LF040, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Probing for SST SST49LF040B, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Found SST flash chip "SST49LF040B" (512 kB, LPC) at physical address 0xfff80000.
Probing for SST SST49LF080A, 1024 kB: Chip lacks correct probe timing information, using default 10mS/40uS. probe_jedec_common: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for SST SST49LF160C, 2048 kB: probe_82802ab: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for ST M50FLW040A, 512 kB: probe_82802ab: id1 0xa4, id2 0x63, id1 is normal flash content, id2 is normal flash content
Probing for ST M50FLW040B, 512 kB: probe_82802ab: id1 0xa4, id2 0x63, id1 is normal flash content, id2 is normal flash content
Probing for ST M50FLW080A, 1024 kB: probe_82802ab: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for ST M50FLW080B, 1024 kB: probe_82802ab: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for ST M50LPW116, 2048 kB: probe_82802ab: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for Winbond W39V040A, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Probing for Winbond W39V040B, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Probing for Winbond W39V040C, 512 kB: probe_jedec_common: id1 0xbf, id2 0x50
Probing for Winbond W39V080A, 1024 kB: probe_jedec_common: id1 0xff, id2 0xff, id1 parity violation, id1 is normal flash content, id2 is normal flash content
Probing for Winbond W49V002A, 256 kB: probe_jedec_common: id1 0xbf, id2 0x50, id1 is normal flash content
===
This flash part has status UNTESTED for operations: WRITE
The test status of this chip may have been updated in the latest development
version of flashrom. If you are running the latest development version,
please email a report to flashrom@flashrom.org if any of the above operations
work correctly for you with this flash part. Please include the flashrom
output with the additional -V option for all operations you tested (-V, -Vr,
-Vw, -VE), and mention which mainboard or programmer you tested.
Please mention your board in the subject line. Thanks for your help!
Erasing and writing flash chip... Trying erase function 0... 0x000000-0x000fff:E, 0x001000-0x001fff:E, 0x002000-0x002fff:E, 0x003000-0x003fff:E, 0x004000-0x004fff:E, 0x005000-0x005fff:E, 0x006000-0x006fff:E, 0x007000-0x007fff:E, 0x008000-0x008fff:E, 0x009000-0x009fff:E, 0x00a000-0x00afff:E, 0x00b000-0x00bfff:E, 0x00c000-0x00cfff:E, 0x00d000-0x00dfff:E, 0x00e000-0x00efff:E, 0x00f000-0x00ffff:E, 0x010000-0x010fff:E, 0x011000-0x011fff:E, 0x012000-0x012fff:E, 0x013000-0x013fff:E, 0x014000-0x014fff:E, 0x015000-0x015fff:E, 0x016000-0x016fff:E, 0x017000-0x017fff:E, 0x018000-0x018fff:E, 0x019000-0x019fff:E, 0x01a000-0x01afff:E, 0x01b000-0x01bfff:E, 0x01c000-0x01cfff:E, 0x01d000-0x01dfff:E, 0x01e000-0x01efff:E, 0x01f000-0x01ffff:E, 0x020000-0x020fff:E, 0x021000-0x021fff:E, 0x022000-0x022fff:E, 0x023000-0x023fff:E, 0x024000-0x024fff:E, 0x025000-0x025fff:E, 0x026000-0x026fff:E, 0x027000-0x027fff:E, 0x028000-0x028fff:E, 0x029000-0x029fff:E, 0x02a000-0x02afff:E, 0x02b000-0x02bfff:E, 0x02c000-0x02cfff:E, 0x02d000-0x02dfff:E, 0x02e000-0x02efff:E, 0x02f000-0x02ffff:E, 0x030000-0x030fff:E, 0x031000-0x031fff:E, 0x032000-0x032fff:E, 0x033000-0x033fff:E, 0x034000-0x034fff:E, 0x035000-0x035fff:E, 0x036000-0x036fff:E, 0x037000-0x037fff:E, 0x038000-0x038fff:E, 0x039000-0x039fff:E, 0x03a000-0x03afff:E, 0x03b000-0x03bfff:E, 0x03c000-0x03cfff:E, 0x03d000-0x03dfff:E, 0x03e000-0x03efff:E, 0x03f000-0x03ffff:E, 0x040000-0x040fff:E, 0x041000-0x041fff:E, 0x042000-0x042fff:E, 0x043000-0x043fff:E, 0x044000-0x044fff:E, 0x045000-0x045fff:E, 0x046000-0x046fff:E, 0x047000-0x047fff:E, 0x048000-0x048fff:E, 0x049000-0x049fff:E, 0x04a000-0x04afff:E, 0x04b000-0x04bfff:E, 0x04c000-0x04cfff:E, 0x04d000-0x04dfff:E, 0x04e000-0x04efff:E, 0x04f000-0x04ffff:E, 0x050000-0x050fff:E, 0x051000-0x051fff:E, 0x052000-0x052fff:E, 0x053000-0x053fff:E, 0x054000-0x054fff:E, 0x055000-0x055fff:E, 0x056000-0x056fff:E, 0x057000-0x057fff:E, 0x058000-0x058fff:E, 0x059000-0x059fff:E, 0x05a000-0x05afff:E, 0x05b000-0x05bfff:E, 0x05c000-0x05cfff:E, 0x05d000-0x05dfff:E, 0x05e000-0x05efff:E, 0x05f000-0x05ffff:E, 0x060000-0x060fff:E, 0x061000-0x061fff:E, 0x062000-0x062fff:E, 0x063000-0x063fff:E, 0x064000-0x064fff:E, 0x065000-0x065fff:E, 0x066000-0x066fff:E, 0x067000-0x067fff:E, 0x068000-0x068fff:E, 0x069000-0x069fff:E, 0x06a000-0x06afff:E, 0x06b000-0x06bfff:E, 0x06c000-0x06cfff:E, 0x06d000-0x06dfff:E, 0x06e000-0x06efff:E, 0x06f000-0x06ffff:E, 0x070000-0x070fff:E, 0x071000-0x071fff:E, 0x072000-0x072fff:E, 0x073000-0x073fff:E, 0x074000-0x074fff:E, 0x075000-0x075fff:E, 0x076000-0x076fff:E, 0x077000-0x077fff:E, 0x078000-0x078fff:E, 0x079000-0x079fff:E, 0x07a000-0x07afff:E, 0x07b000-0x07bfff:E, 0x07c000-0x07cfff:E, 0x07d000-0x07dfff:E, 0x07e000-0x07efff:E, 0x07f000-0x07ffff:E
Erase/write done.
Restoring PCI config space for 00:01:0 reg 0x6d
Restoring PCI config space for 00:01:0 reg 0x90
Restoring PCI config space for 00:01:0 reg 0x8c
Restoring PCI config space for 00:01:0 reg 0x88

My problem is the other bios is'nt mine and i must give back it saturday

what is curious is that last month I managed to flash the bios without any manual manipulation of mainboard with the acer software from a windows live cd