Yeah I recognize the problem.
Sometimes it helps pressing F11 (switch to object inspector) and then F12.
I am able to confirm on that. sometimes that helps.
I've come so accustomed to it that whenever my workbench is empty, i'm pressing these f11/f12 combination a couple of times without giving it any thought.
I'm a bit bit puzzled by garlar27's experience, as was stated that sometimes it works, while other times (particular projects?) not at all.
As far as i am able to remember, i've only experienced this twice or thrice, and for such cases, closing down lazarus, starting it again and loading the project 'fixed' that for me.