EB Calling Legacy Option ROMs
Looks like the BIOS and the ROM on the network card are incompatible.
Try disabling the option ROM (maybe a jumper on the network card ?).
You will lose the ability to do a network boot though.
You could also try to change some BIOS settings (for example settings like "keep video mode for option ROMs").
Are you using EFI boot, or legacy BIOS boot ?
That may make a difference too (although you probably will have to reinstall the OS if you change your boot mode).
Guys, (and girls)
I believe the solution is not with the card, because the card does not have jumpers (at least something is changed in 2010...). In a DP55WB board, remove the card, boot the system, go to BIOS. Select power. The last option is PCIe ASPM support. This is probably disabled. enabling it in my case solved the problem and system boots