what distro are you on?
 
Ubuntu Studio Feisty 7.04.  I usually do load some GNOME things ocasionally and I wonder if they are staying in the system... I'm running a P4 1.6 GHz 384 MB RAM so I need to keep the memory freed up.  I will look into the running processes, I haven't taken the time to find out what is what yet.  Application startup (including pd) is slow and the pc doesn't seem to be paging or anything to disk...
 
km