I think I have identified the problem, but not a final solution.
I realized that a clean install would work fine until I updated the packages. I tried updating from different repositories, but that didn't help. I got an idea that maybe only one package was causing the problem, so I tried updating each package individually instead of using the "Mark All Upgrades" button. After each upgrade I would restart the computer. Everything worked fine until I reached the package 'fuse'. After upgrading 'fuse' the computer locked up. I did a clean install. (i.e. format the entire drive and install PCLOS.) I then upgraded 'fuse' from a different repository, and it still caused a lock up. I then did another clean install, selected "Mark All Upgrades", deselected 'fuse', then hit apply. The computer is no longer locking up. According to Synaptic, the installed version of 'fuse' is 2.7.4-2pclos2007, and the latest version is 2.7.4-5pclos2009. Obviously, the latest version of 'fuse' has a bug that makes it incompatible with my system.
How would I get this information to TEX or whoever it is that would fix this bug?