AFAIK, the AEP builds are "plain" compiles of the CVS, without additional patches (that's what i've been told by one of the DOSBox devs).
On my system, i have the "sticky key" problem when "priority=high,normal" is set in dosbox.conf (it's the default setting). Changing the entry to "priority=normal,normal" fixes the problem.
Another alternative might be to play the Amiga version on WinUAE. With the help of WHDLoad on the Amiga, the game can even be played from HD. On the Amiga, there's an AGA and a CD32 version of the game, which should look better than the original DOS version (more colours, higher resolution). I'm not quite sure about that, though, as i don't know what the DOS version looks like exactly.