Ah one of the games that was so damn cool that many of my pc friends hanged around my house just to play nemac 4
...
anyway i dont use uae, but i can tell you that when i run it here on my machine i dont see any of your symptons.
but then again i use an amiga .
good luck on that but it seems you should try to test the controller in the panels of windows (its seems to be out of sync or something... center it and it should be fine...)
cheers
pps:u might wanna get yerself an amiga if u wanna play many games perfectly.... (just a hint... check ebay for diffrent good deals on the hw...)
