are linux skills important for someone interested in making a career out of computer networking?
lets say CCNA, CCNP.

so far the most useful programs i been looking only work in windows, i am still able to run them via virtualbox , but some of them get a bit buggy due to virtualbox experimental 3d support.

i run ubuntu as my main system and xp in virtualbox when i need some windows program.
i wouldn't like running linux via virtualbox. but school and some other programs are making my life a little bit difficult due to windows programs.

The most useful programs only run on windows?? I think you'll find that wireshark runs on linux just fine. Ain't no more useful program for network guys.

In general though, linux skills are extremely useful, but their use has nothing to do with your discussion at all.

Many many network devices are built on top of linux or bsd systems, and whilst they will generally (but not always by any means) have their shells to configure it, it's rate to not need to go under the covers, or merely benefit from knowing about the guts of the devices.

wireshark runs fine, iam talking about the cisco programs for ccna prep stuff, packet tracer, TestOut, and some other freeware networking tools i havent been able to run via wine.

Sure, but CCNA prep has very little to do with the long terms benefits of understanding Linux. If you can't make them run through wine, then I'd personally just use a windows VM or something whilst I'm studying.