Thanks for trying this out as it has put me on to the solution. This seems to have definitely changed since .227 as I had copied ini setting forward and would have expected them to work the same. I tried setting mouse to 1 as you did, but this didn't work for me (even with a newly generated mame.ini); however, on a lark I set "multimouse" to 1 and this did work. This is interesting and probably has something to do with the fact that I have multiple "mouse" controls (I have two spinners, one X and one Y, and a trackball which all behave as mouse controls). Also interesting is that setting multimouse to 1 in mame.ini fixes Cameltry and Cisco Heat but breaks Tempest and Centipede. This is easily dealt with by moving the multimouse setting into the individual game ini files, but is definitely a different kind of behavior than previous versions. Anyway, looks like I'm back in business. Thanks, Scott, for the information!