Yes. I've been using Kubuntu since version 6.04 until know and have had only 2
or 3 successful upgrades. The rest, including the 9.10 upgrade, ended in
failure. Luckily, this time I had burnt a DVD of 9.10 and verified the MD5 key
(the first download was bad) before attempting the upgrade. When it failed, I
just proceeded to do a fresh install.

I think the best solution is to mount your /Home drive in a separate partition
thus allowing you to re-install your system as often as you want without the
need to backup your data. Besides, this lets you clean out all the bad
experimenting you may have (I did ;) ) on the O.S.