MAME32 and Trio Linker adapter

[Radio]

Howdy.  I'm hoping someone here can help me. 

I don't have the room or resources for a cabinet at the moment  so I've settled for the next best thing and bought myself a Dreamcast Arcade Stick and a Trio Linker Plus II usb adapter. 
Only problem is I'm trying to test out if I've configured the controls properly for MAME32 and I'm finding that every time I press esc on the keyboard MAME freezes up, the sound stutters and I can't minimise out of the program using alt+tab and end up having to reboot the computer.  MAME32 doesn't do this when the adapter isn't plugged in. 

I didn't map any of the controller's buttons to the esc key so I'm not sure what is going on here. 
Anyone have this adapter or any tips for getting my controller up and running?