Couple of problems/suggestions
 

First, I think there should be in options(in the playerlist option button) that should allow to disable docking, much like other docking applications have. Also, I don't know if you can, but I thought you'd be able to dock the playerlist inside the Graal window/onto it?

Also, about the tray thing, I think that needs to be changed. I hate being asked that everytime I go to change Graal, maybe have an option for that, or have a check thing if you want it to be shown again.

And for the problems/bugs, the playerlist constantly pops up over other windows. I opened up firefox and tried writing this and the playerlist kept opening up.

EDIT: using Windows XP: pro