Still doing some checking of my own. I can't get it to run in Mame32 (.55) on my old Win98 box either. With that machine, it's locking up the monitor, reassuring me that it's a resolution/refresh problem. However, I pulled up an old version of DOS Mame (.66) on that computer and it works fine.
I've now installed .62 Mame32 on the WinXP box to check if it is that box/drivers and Rampage works fine on that box. Tried the same settings (default) on Mame v99 and still no luck.