I find Deskzilla invaluable, as I do most of my compiler patching on the train, without an internet connection. Plus, the query support is better than on-line bugzilla, so it's much easier to find stuff.
Deskzilla Lite (free download from http://almworks.com/) has just added
http://d.puremagic.com/issues/ to their list of supported open-source
projects.