How to make an upgraded system clean by automatically removing abandoned config files?

I've noticed some abandoned configuration files have been left lying around my harddrive, which by their existence have a (sometimes negative) effect on my upgraded system. They were installed by packages in lenny, but would not be installed in a fresh installation of squeeze. Despite unmodified co

Weird icon colors in squeeze (ppc). Which package should i file a bug report for?

Since my upgrade to squeeze, many menu icons, scrollbars, and some images displayed in browsers have been displaying funky colors. I don't know which package is causing this bug, so can anyone offer any advice? Here is a picture of what I'm talking about, using the clearlooks theme: http://imgur.c