RhoSimulator isn't a very good emulation of real device browser. I wouldn't use RhoSimulator to debug UI issues. (I don't use it at all.)
I always use either a real device or the appropriate manufacturer-provided simulator. (e.g. I debug iOS apps in either the iOS Simulator or real iPhone/iPad. Not RhoSimulator.
RhoSimulator can be useful if you need to debug some Ruby code.
Yes I don't care that it doesn't work in rhosimultor, but as I mentioned it behaves the same way in win32 builds, which is my main concern - I should have made that clearer.