What are your system specs? What is the speed of the XMS and PNY memory? Reset the BIOS to default timings and see if all the memory works together. How many black chips are on the new and old memory?
Crucial Performance Lab
The Memory Experts(SM) at Crucial Technology is now on board to give you straight answers to your memory-related questions.
When responding please provide your full system specs; hardware and software, OS, BIOS, drivers Etc. You can e-mailmemory related questions to email@example.com