Most apps won't start

[Chris]

Hi guys,

I've had this problem on more then one Ubuntu and Kubuntu systems.  I'll
go to start and application and it will attempt to start.  The task bar
and bouncing cursor icon will indicate that the application is going to
start, but nothing happens. Then the taskbar and bouncing cursor icon
disappears and nothing happens.

As an example I just plugged in a 512mb SD memory card to upload some
pictures to this Kubuntu machine.  When the card was inserted in the
card reader it promts me as to what to do.  I choose to open it in
DigiKam. It open I uploaded the pics off the card to the PC.  An hour
later I tried to open open the picture with DigiKam and it starts the
load...and does nothing but bounce the cursor icon and show DigiKam in
the taskbar...then it doesn't load and the task bar and cursor icon
disappear.  This happens with some other application too.

Any idea on how to fix this?
Thanks guys,
Chris