I was using a version of GitX from what appears to be the original source at gitx.frim.nl. It’s been acting really weird, doing things like not hiding the program and not responding to simple requests for new windows, and I thought perhaps it was related to my recent upgrade to Lion. I looked around, and gitx.laullon.com maintains a much more recent codebase for your download pleasure, which you can inspect at laullon’s github repository. Download, unzip, run, done. Same program, but much better behavior.