Mushkin 2gb kit RMA?

[Bones]

I got the Mushkin kit when i was on special a couple of weeks ago, and since then i have been having memory errors in windows. I get then while using Steam or doing simple things like using winamp. I ran Memtest86 left it running for 2 hours odd, it didn't pick up any errors. how long should it run for? OCuk guy on the phone said to run memtest86 but if that doesn't pick up any erros can i still RMA it :S i hope so