"System has failed to Post" error after adding new Corsair memory

I'll preface this by saying I know just enough about computer technology to be dangerous (in other words, very little).  Here's my problem:

I have a 2-month-old XPS 630i system with the Intel Q9550 quad core processor.   Four days ago I replaced the four 1gb stock Kingston memory chips with two 1gb Corsair chips (I'm awaiting arrival of another set).  The new chips are the XMS2 DHX type; they're the CM2X1024-6400C5DHX, 800MHz, 5-5-5-18. 

The memory works fine.  Yesterday, I downloaded a trial version of "Virtual Drive" in order to play PC games without having to insert a play disc.   There were a few initial glitches, but the program worked fine.     

Also yesterday, I downloaded the BIOS 1.0.12 update from the Dell website, but did not install it right away.  

When I booted up the computer this moring, I got an error message:  "System has failed to POST.  System is using default settings for this POST attempt.  Press F1 to continue.  Press F2 to enter SETUP to adjust oc/ov settings."

I pressed F1 and the system booted up fine.  I imitially thought that this error message may have had something to do with the "Virtual Drive" installation, so I uninstalled it.  During the uninstall I got an error message saying that one of the file needed to continue with the uninstall was in use, but I hit "ignore" and the uninstall completed.  On reboot, however, I still got the "System failed to POST" message.  So, I did a system restore back to yesterday moring before I made any of the changes discussed above.  The sytem restore worked fine, but on reboot I still got the error message.  I hit F1 again, and the computer booted up fine.

Next, I re-downloaded the BIOS update from the Dell website, and this time I installed it.  The installation went fine, but I still got the same error message.

So, I did some online research about this error.  It appears that oc and ov refer to overclocking and overvoltage, which apparently can be adjusted in the BIOS.  I have never overclocked the computer or messed with any of the BIOS settings, and i don't want to make any changes to the BIOS unless and until I know what I'm doing. 

I also learned that at least one person who has installed new Corsair memory has had a similar "failed to post" error message.  I then ran PC Wizard to look at the CPU heating information, which the Corsair post seemed to indicate could have something to do with the problem.  My CPU is running at about 48 degrees C, which I understand is a little higher than the typical 38 - 42 degrees.  All of the fans in the case are working fine, including the CPU fan.    

Anyone have any thoughts about what might be causing this error message, whether it poses any threat to my system, and how I might fix it.  I'm contemplating doing a complete reinstallation of the operating system, but obviously I'd rather avoid that if I could.

Any thoughts would be appreciated