"There were frequent freezes, apps took forever to load, and the cursor often moves in a jerky manner."
As a guess I would say that these are all possibly symptoms of a swap problem. Check /etc/fstab to see if swap is configured correctly. Have you, or the SuSE installer, run mkswap? Is swap big enough? Do you have a swap partition or are you running a swap file (sloooow)?
Or do you have enough memory that swap cannot be the problem and it is something else?
" I don't see how this can be a hardware problem."
I had a long running problem where a IDE controller worked just fine (more or less) with just one disk attached but flat out would not work when two disks attached, one to each cable.
Be prepared. Create a LifeBoat CD.