What is with calling applications stupid names like "helix player" ?
Infact, helix-player is a replacement for the realvideo/realaudio application in debian testing however it does not play the .ram feeds which is exactly what you would use RealPlayer for? What's the point of replacing it with a newer player only to find it doesnt play what you wanted it for?
Several applications do not handle a situation where your disk is current fully or becomes read-only, such as NFS situations or your laptop running out of space, this isnt such a big issue as the user can avoid it however it DOES happen, applications such as firefox will loose all of your browsing history (why not just not add any history? I cant see why it would throw out your previous set),
MySQL will give you an "error 28" when there are too many files in /tmp.
Earlier versions of KDE/KDM would get stuck into a KDM crashing loop and you had to reboot
Im sure there are more.
There are a number of serious printing related issues with mozilla, at first you may think ahh it doesnt affect me, but try printing your itinerary from Singapore Airlines or your Yahoo! Mail, chances are you will miss an important section of that sheet, espically if its enough to cover more than one sheet of paper.