I think, I have found the failure.
if write_protect_vgabios() is called, it searches by dev_find_device(0x1106, 0x3123, 0) for the device dev
if dev valid, it write protected the vgabios.
But it seems the via epia-ml vga device ID is 3122. I have seen this on the console output before write_protect_vgabios is called.
Found VGA: vid=1106, did=3122
Unfortunatly the printk_info messages "write_protect_vgabios" comes before the bios is protected.
I will try a new Linuxbios with changes on dev_find_device() and hope all will work fine :D
chris