Yeah I noticed this problem with 3.0.2 and checked the forums knowing others most likely had the same issue.
I know you can configure per user in the settings and there's also the interface config.inc.php which states the "default" theme.
I'm yet to install 18.104.22.168 but got issues now as my ispc3 code has hacks and need to diff out my changes
@Till: Maybe a themes site/page should be made for contributions, i'm sure there's quite a few artists out there. I'm missing my likings of icons in theses
so I'm writing my own *cough cough* template. :P