I find it funny the day after I make a glowing comment about support in FOSS projects, I run into a snag that is not documented anywhere.
I filed a bug on it, but was able to resolve it myself. Trying to look at this from a newbie or non-technical point of view, I’m not sure how I would have reached the same conclusion. I happen to know that all *-dbg packages are “debug” packages and are therefore implicitly optional. Removing them was a reasonable step, and it happened to fix it.
However, as a normal end-user, I am not likely to have known about this. In fact, when seeking help, I may have been asked to install these packages to gather more information about a problem.
This is not a good problem to have during an upgrade process. But I did draw this problem down upon myself by installing packages from the backports. However, I seem to recall this same issue when performing a supported upgrade from the previous version of the distribution (Kubuntu 9.04) to the current version (Kubuntu 9.10).