PokerTracker

I've been having to shut down and restart poker tracker to get HUD started. Usually HUD pops up right away after the restart.

Are you using PAHud with PT2, or PT3?

PT3

Please restart PT3 with the Logging Enabled link on your start menu, play normally until the HUD disappears, and then report this problem - the log files will help us considerably in figuring out what is going wrong here for you.

I can't find the log enable link on the start menu. Can you walk me through it? I found some "Poker Tracker HUD crash" files in my documents, would these be helpful?

You can also enable logging within PT3 and restart.
See the Tutorial: Submitting a Bug Report.