RAM and Teamspeak?

In a rig I have 4x512 of Corsair 8000UL on a P5W. TS(teamspeak) works perfect. Got bored last night so I threw in 4x1Gb of OCZ VX2. Could hear everyone on TS, but my mic(Medusa 5.1 headset) wouldn't work. Checked everything in Sound and Audio devices, Creative Console, etc, and still no mic. Put the Corsair back in and the mic works.

What is up with that? XP Pro x64 and it recognized all 4 gig's. Anyone have any ideas? I'm just curious.