GTX 750 in legacy mode in P6 series, delays and BIOS inaccessible.

Hi, 

    I have a Pavillion P6-2130in 

http://h20565.www2.hp.com/portal/site/hpsc/template.PAGE/public/kb/docDisplay?javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&javax.portlet.prp_ba847bafb2a2d782fcbb0710b053ce01=wsrp-navigationalState%3DdocId%253Demr_na-c03225008-12%257CdocLocale%253D%257CcalledBy%253D&javax.portlet.tpst=ba847bafb2a2d782fcbb0710b053ce01&ac.admitted=1406109850963.876444892.492883150

with a Foxconn made Cupertino2 motherboard with AMI BIOs version 7.16

http://h20565.www2.hp.com/portal/site/hpsc/template.PAGE/public/kb/docDisplay?javax.portlet.begCacheTok=com.vignette.cachetoken&javax.portlet.endCacheTok=com.vignette.cachetoken&javax.portlet.prp_ba847bafb2a2d782fcbb0710b053ce01=wsrp-navigationalState%3DdocId%253Demr_na-c03225008-12%257CdocLocale%253D%257CcalledBy%253D&javax.portlet.tpst=ba847bafb2a2d782fcbb0710b053ce01&ac.admitted=1406109850963.876444892.492883150

I bought an MSI N750-1GD5/OC (a GTX 750) video card that I have been able to somehow install in legacy mode- by switching the video card switch to 'legacy' position and also by disabling EFI/ UEFI devices in BIOS. I've also changed the PSU a month ago to a Seasonic 400W, and I'm fairly certain my problems are unrelated to PSU issues. The video card takes in onboard power (no external power connector) and works just fine once windows (or Linux) start, but 2 problems remain. I'll appreciate any assistance regarding them.

1. I can't get to the BIOS at all with the new hardware plugged in. Can get to BIOS only when I disconnect the new card and plug monitor to motherboard DVI socket. With the new card plugged in, this is the boot-time behaviour:

post screen---25 seconds---beep---25 seconds---beep---35 seconds---beep---Windows starts

If I press F10 key at the end of 35 second beep, I get a black screen that hangs. I've already looked at beep codes of the AMI board and it's hardly any help.

2. The computer can't resume from hibernation. Again black screen/ hang. I've disabled hibernation on my desktop for now.

It seems both issues are related to problem with initial handshake with the new video card, and possibly related to power management issues because the card *is* recognized under certain circumstances. I'd really appreciate any help from the forum experts to fix these 2 issues- inability to enter BIOs, and resume from hibernation. 

Currently, my BIOS is setup for legacy-device-only boot; Data Execution Prevention to Disable; Virtualization to Disable; SATA power management to Enable; S5 Maximum Power Savings to Disable; S5 Wake on Lan to Enable; PCI SERR# Generation to Enable; PCI VGA Palette Snooping to Disable.

This is the exact BIOS interface of my machine: 

http://h10025.www1.hp.com/ewfrf/wc/document?cc=us&lc=en&docname=c03235578#N136

Many thanks to the helpful experts in advance.

PS-

The problem is obviously BIOS related, and it's a pity HP does not care enough about its customers to ask Foxconn to fix what is surely a trivial issue. Tens of thousands of these foxconn mainboard fitted machines must have been sold! Do so many customers not count for HP? Guess what, the customer isn't going to be hung-ho about HP hardware the next time she/he has to make a purchase.