More help requested

[Anthony Papillion]

Hello Everyone,

I'm trying to troubleshoot an issue that's been going on for a while and
I've yet to be able to figure it out - or even get a clue as to what
might be going on.

First, here is my hardware:

Acer 5100 Laptop
AMD Turon 64 X2 TL-50 Processor (1.6Ghz)
3GB RAM
120HD
ATI Radeon XPress 1100
Ubuntu Linux 10.04 LTS

Originally, I installed Ubuntu on the internal hard disk drive. I kept
experiencing freezes with the screen filling with upright gray and black
bars. At that point the computer would have to be manually rebooted by
pressing and holding the power button.

After some poking around, I determined that there was a bad area of the
internal hard disk drive and installed Ubuntu on a new, removable 120
Maxtor USB drive. Things seemed to work fine.

However, sometimes, and this regularly happens after a few minutes to a
few hours of use, the system will stop responding.  The wifi signal
locator will turn to a red circle with a horizontal "-" sign in it and
when I click it, the entire thing is filled with little [][][][][]
instead of text.

At that point, even though the mouse is still active, programs stop
responding and the system must be rebooted by holding down the power
key. Once rebooted, things will run fine for a while and then it will
happen again.

I've looked at the different logs and, unless I simply don't know what
to look for, I'm not seeing anything that would indicate a problem. I've
logged the exact time the problem occured and looked through logs for
anything happening at that time (in the ones that specify even times)
and can't find anything.

This is driving me insane. My laptop is totally unreliable. As I write
this, I'm not even sure I'll be able to send it. Can anyone point me in
the right direction on what this might be and what I can do to find out
the source of this problem?

Thank You,
Anthony