Just recently upgraded the memory, formatted the HDD and switched over to Windows 7 Pro 64bit last week. I have been getting numerous BSODs that seem to happen every time the machine goes to sleep. Hibernate and Hybrid Sleep are both disabled. Might be something totally different but I'm scratching my head on this one. The crash report is attached and the previous and current config is below are far as what was changed. Thanks for the help!
Windows 7 Pro 32bit (Full Retail)
3GB DDR2 PC2-5300
Windows 7 Pro 64bit (Full OEM)
6GB DDR2 PC2-6400
Despite Dell stating the machine is only good up to 4GB, the Intel P965 can go up to 8GB and both Windows and the BIOS recognize the 6GB.