I recently re-installed my BT4 R1 to BT4 R2
(tried the upgrade procedure at first but i had quite a lot of error messages relating to dpkg when running apt-get and got tired of messing around with what was probably an error caused by my own messing around )
Anyways, I formatted the ext3 and swap and installed R2 from a CD.
The only specific customizations I have made to the OS so far is to install dropbox, and follow the wiki guide to installing NVIDIA drivers & CUDA for Pyrit.
Besides that, the OS should be completely clean.
This set up is on a desktop computer running on an i7-930 *not clocked*, 6GB memory, I have a 128 GB disk dedicated to running my OS'es (dual booting with win7x64).
Usually I would suspect this behavior to be caused by some sorts of HW error - however I can run Win7 without any issues at all and I had no similar errors when I was using BT4 R1.
I contemplated whether or not to put this in the bug sub-forum but I have too little experience troubleshooting linux performance and don't know where to start looking for error logs etc so before I can be sure that this is no fault of my own I decided to place this in the beginners forum.
If anyone has any idea of where I can begin to look for helpful error messages, KDE log, or some sort of event viewer type application - please let me know.