Vista Ultimate 64 BSOD not sure why?

I've started receiving the dreaded BSOD the last few days. I've been trying to debug the mini.dmp files, but have had little luck. I can't think of anything that I have changed in the last few days. I installed new memory about a month ago after having problems with rebooting, but that problem appeared much different than this one.
I have attached a .zip of the minidump files. Any help would be greatly appreciated.

Inside the 4 MiniDumps:

Still having problems

Thanks for the help, I was running memtest on all of the modules individually and all 4 gigs together. I ran it with all 4 overnight and after 5 passes I had no errors. I have even tried taking out two of the ram modules, but it is still crashing. Beginning to believe this is not the problem. I have attached 6 more .dmp files if anyone can help tell me what the hell they mean.

Thank you....

Reinstalled Vista 64 still having trouble

I reinstalled Vista 64 and everything seemed fine for 7-8 hours. However once again the system had a BSOD and rebooted. I have run a ton of memory tests, and now don't know if it's the hard drive, video card, sound card, or MOBO. Once again any help would be much appreciated, since this is driving me crazy.....

5 of 6 minidumps all point to memory corruption. Bad memory has been known on occasion to pass MemTest which is why a minimum of 7 passes is recommended.

1. Run the test on each of your sticks one at a time again.

2. It could be your voltage settings for your RAM. What is the recommended voltage and what does your BIOS indicate as the current voltage?

3. What is your motherboard? ASUS for one is well known for being picky about RAM.

4. Try running with 2 gigs and see if that brings stability.

5. CCT posted this link in another thread. Seems you are not alone. http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=1292561&SiteID=17

Test one stick of RAM at a time for a few hours then shutdown the system and replace the RAM stick with another one do the same thing. Continue until you hit the BAD RAM. Their is a better program to use to tell you which is BAD in less than a second. Window Memory Tester but you run it in DOS. Better than Memtest that everyone uses. Find out what RAM was tested on your MOBO and use that RAM only.