Cool, you found a solution.
Most of my test are done on the Minimig(68000) so I don't have the F10 function :P
But I'm going to try this on my 1200 ASAP.
"Some" are probably the games that doesn't rekick, and TL isn't wiped from the memory.
So when you exit the game you return to TL (with a bug that I'm going to check). a few messages someone wanted to return to TL by pressing F10. So it's going to be possible for "Some" games...
If you want TL to be wiped from memory, use the RAD. (but as you are runing in WINUAE you probably don't care :-)
Well, at least your problem made me improve the code...