JFrame invisible refuse to paint windows content tho everything else runs?

Wtf just happend?
I got tons of code I can NOT publish an example here. No possible way.
I only need to know, what are the common reasons that JFrames fucks up when painting it's contents?

It isnt hoged up as I can minimize and maximize, but it simply doesnt repaint anymore. Tho the repaint method is called over a 30 times per second.

It works when I add the jpanel with the game graphics in the begging.
If I remove the menu then add the game graphics panel, then it doesnt work.

Can't help without seeing code, but can't help if you have tons of code. You have your work cut out for you: Cut out code a bit at a time til the error goes away and that might be your offending code. Use a debugger or println statements to watch the state of your program as it rungs.

So I did as Iv done before, Replace it using a JCardLayout JPanel. Sucks that I will never figure out whats causing this..