After updating from Ubuntu 13.04 to 13.10 I found that my SmartGit was broken. I could just use the standard git commands but that's boring and I like to have a GUI so SmartGit is nice for that and it needed to be fixed. Apparently Ubuntu 13.10's GTK libraries aren't very compatible with SmartGit, any version of it. The fix is simple.

1. sudo nano smartgithg.sh
2. Add the line UBUNTU_MENUPROXY=0 just underneath the comments at the very top of the file.
3. Save.

That's it! Fixed. Hope this helps. I'll update when there is an official patch. In the mean time this works fine. UPDATE They just released RC1 which fixes the problem. Download SmartGit 5 RC1 here.