Linux hangs, and logs out user when resizing/scrolling windows

[ngrieb]

I recently installed Ubuntu 8.10, and am having multiple problems. I am not new to Linux, but I have never set it up myself for personal use, and having quite a few issues. I have an odd problem with resizing, dragging, or scrolling using my mouse (Logitech MX518) which seems to work properly otherwise (all other buttons are functioning as they did in Windows),but sometimes Ubuntu just logs me out, when messing with window size. Ubuntu also hangs quite a lot, while I am doing simple tasks like copying data to the hard drive from DVD. I am also not able to change the desktop setting to a descent size, it starts at 800x600 even when I reconfigured xorg.conf (I can chose a higher screen resolution when booting in "low graphics" mode. All of these problems are starting to anger me(especially the log out behavior), because I cant seem to make them go away.

I think this is a memory issue, because of the broad scope of the failures(is there a virtual memory in Linux?). I also received the "Buffer I/O Error on dev Sr0" warning on install, and thereafter a few times, if this has anything to do with it. How do I preform a mem check and/or hard disk check? Any other ideas?

I am running:
AMD Athlon 3000+
nVidia MX 4400 (I think...did have an nVidia6800XT :mad: )
Harddisk:?(Really don't want to reboot to find out)
DVD:?
DLink AirPlusG Wireless Card

I use Linux at work and enjoy it, so I would really like get this problem fixed ASAP.
Thanks in advance for any help.