On after trying to print a complex document (with lots of other programs running) Wednesday morning, when I hot home Wednesday evening I found that my main desktop machine had hung (black screen / screen saver). I'm still not sure if this was due to a hardware issue (likely a hard drive write-back failure) or some other software bug. After a bit of fiddling attempting to recover, I went ahead and installed the AMD64 version of Ubuntu's recent Dapper Drake (ver 6.06) release onto an empty partition. It took a couple of passes to get it up and going, but all seems well at this point. I also had to set back up a few hardware items like my $29.99 HP Photosmart 1215 printer.
Fortunately all of my personal data was on a separate hard drive partition and was quickly and easily backed up to an external USB hard drive. So with the new Linux install I still have all my settings, preferences and data files.