Tommy Thorn [off-list ref] wrote:

Just a quick heads-up: I was running a dual screen setup with gitk on my 
2nd monitor. When I later started gitk up without the 2nd monitor, the 
gitk window didn't appear. Given the time between the two sessions, it 
didn't occur to me what the problem was.

Gitk should probably validate the "set geometry(main)" variable against 
the current resolution.

Sad to say but this is a known issue with both gitk and git-gui.
Both applications save the prior geometry and restore it during
the next run, but neither validates the new geometry makes sense
with the current available desktop space.  :-\

-- 
Shawn.