Advice - bad RAM

[Chris Mohler]

OK, so my system has been increasingly unstable over the past week.  I
was hoping that b/c I tend to install everything under the sun and
hack it to bits that I was facing a software issue.  Symptoms: FF
segfaults, various lookup symbol errors, XP (in VirtualBox) throwing
BSoD, xorg crashing.

I was thinking of doing a fresh install of 9.04 (currently 8.10
upgraded from 8.04 - I usually do a clean install but I was just
curious last time).  But before the install, I ran memtest86 and lo
and behold there were 10 errors in the first minute.  I doubt this
bodes well.   I'm doing some more research right now, but wanted to
know if anyone has first-hand experience with dealing with (possibly)
bad RAM.  I know that there is (or was) a kernel-level program for
"sitting on" bad addresses - anyone used this?  Also - anyone ever
have false positives with memtest86?

I'm also probably hunting for new RAM - this machine is a Dell Vostro
1500 laptop.

Thoughts, comments, advice welcome.
Chris