I had the same problem in vmware just this week. Works in bootcamp, though.
I have the PSUMoni program connecting to my 2140 on my desktop under Boot Camp, but if I try VMWare on that computer it doesn't see it, and reinstalling the driver causes a Mac kernel panic - the gray screen descends. Same thing if I install the driver under Parallels on my Mini.
I don't have Boot Camp on the Mini and don't have another Windows install to use on that. I want the PSUMoni program to connect for obvious reasons, and because it might be able to help me diagnose why my install isn't getting an output from the 2140.
I find it very interesting that the same kernel panic on Leopard occurs when installing the driver under two separate virtualization programs - VMWare and Parallels - at exactly the same time, when installing the "mshusb.sys" (IIRC) file. Anyone have the same issue and overcome it?