I have been using my Debian install for a while and I kept dist-upgrading because I didn't want to reinstall everything after every new Release. But now I'm starting to get a few errors at the reboot with the drivers etc. Is there anything I can do to "clean up" my install?
How does a man eat an elephant? Simple - he eats it one slice at a time.
Same analogy goes for your debian install - identify the errors, and tackle them one by one through the debian forums, or even superuser.com.
on the topic of a general cleanup, you can consider apt-get with a few options/flags :
Refer to the apt-get man page for information on what these options/flags do.
Be sure to never, ever jump a version.
When I tried to upgrade from Etch (4.0) to Squeeze (6.0), all hell broke loose. Upgrading from Etch (4.0) to Lenny (5.0) and then to Squeeze (6.0) works quite well.
I've now done this a couple of times because I keep some 486 or Pentium machines running as print servers or proxies, for which they are still more than good enough because no X or desktop environment is required, and Etch is the last version that can still boot from floppies.
You may run into some issues because drivers have changed or module options are stored in different files or the way the X window system works has been modified from version to version, but these are issues you should address one after another.
Also, I've found it to be really helpful to do as much as I can with aptitude because this is the easiest way of having apt tell me when I'm about to do something stupid that may break my installation.