8.04 randomly locks up.

[elmo]

This my fifth attempt to send this message. The first four times were 
tried when I was running UBUNTU 8.04, twice with CD version and twice 
with the DVD version, but freezeup occurred and the messages couldn't be 
sent.  I finally had to resort to Windows XP to send this message.

I have both, the CD and DVD, versions of 8.04 ubuntu installed and I'm 
having a freezeup problem with both. The two were downloaded from 
different sources.  The earlier versions (6.04 - 7.10) didn't have any 
such problems and neither does it occur in Windows. 

The freezeup seems to be completely random but seems to occur when I 
move the cursor
to select some operation.  It doesn't happen every time I move the 
cursor, it is completely random.

When freezeup occurs, mouse operation and none of the keyboard keys have 
any visible effect except pressing the power button on the computer to 
shut it off and start over.

I'm quite sure  I have the proper (for my computer) versions of  ubuntu 
installed.
All of the earlier ubuntus never gave me any problem.
Could this be some flaw in 8.04?

elmo