alright with default values (cycles & core =auto, 32 Mb RAM, etc)

32mb is no default value. Try without a frontend, using a clean dosbox.conf
and see if fullscreen makes a difference. CF1 works just fine here.

I'll be damned... it DOES work with plain DOSBox. There must be something off in the config I'm using within DRF.

Thanks for the help.

please post if you figure out what is wrong

I think I got the problem, it's the "autolock" feature. If it is on, the game behaves normally. If it is off, the mouse behaves errativally.

Can anybody check this against their versions of the game?

Which autolock? Does it behave the same if you change the autolock value
in your clean 0.72 dosbox.conf?

Mouse autolock. And yes, it does happen under DOSBox v0.72 and a clean dosbox.conf. I just tried it before posting this, to be sure.

Again, it would be nice if anybody else could reproduce it.

well autolock=false is less compatible with games that read the mickeys instead of the coordinates.
you can lock the mouse btw with middle mouse button for those games.

Thanks for the quick answer. BTW, are there any games known to respond badly to autolock=true?

no, autolock=true is the most compatible.
autolock=false exists for people that don't like the fact that the mouse is locked to the window.
but it is always less compatible.

Good to hear that. I've just suggested Alexander to make "autolock=true" the default setting in DFR, and asked him to check if any other options are set different in DFR's default settings than in the default dosbox.conf.