RAM Preventing Wakeup?

Ask the Doctor LogoDoc, I have a 2-year-old Dell XPS 720. It has a 2.4GHz Intel Core 2 Quad Q6600, a GeForce 8800 GT, and runs on Windows XP. It shipped with two 1GB DIMMs. A few months ago, I decided to upgrade to four 1GB DIMMs. I bought the RAM from Crucial. The machine boots and shows the correct amount of RAM and runs great. My problem is coming back from a sleep or hibernate state. The PC’s hard drive just spins and nothing happens. If I take out one DIMM, it will boot right up. I can shut it off, replace the fourth stick of RAM and it comes right up. It doesn’t matter which stick I remove or what slots they are in. I’ve updated the video drivers and BIOS but it didn’t make any difference. Any ideas?

—Jim Leiferman

Read the Doctor's answer for Jim after the jump.