I use java-based apps mostly, but there are quite a few good trading apps out there for linux and Mac OS X. Search back through old threads in the software section and you'll find many links (search for 'linux' or 'mac' posts by 'cable' and you'll find what I babbled in the past, complete with links). And I have run Windows trading software (Amibroker) under the linux Wine emulator, and it ran just fine (also mentioned in my past postings, IIRC). Beats the hell out of Windows, and I'm saying that from experience.
next step is call your broker, some of them is pretty knowledgeable since most client tend to have the same problem.