An idea:
If I remember correctly (and there's no guarantee of that
) many Broadcom devices work well using NDISwrapper, combined with the WinXP/Win2000 driver files.
NDISwrapper is a wrapper driver, designed for using WinXX drivers under Linux, which is not really a lovely solution, but one that works in a pinch.
Google for NDISwrapper, go to the website, and check the 'supported/working devices' list(s) and see if your device is listed there.
Good luck
Sasha