flv without a plugin?

I’m trying to get flv on a site currently under development, I have created flv files and custom skins which all work fine.
When I try to integrate them all into wordpress nothing happens, they simply don’t work.

I’ve tried changing the links within the files and everything else I can think of but still no joy!
After that I tried some (maybe ALL!) of the flv plugins available but cannot seem to get any of them working with my custom skin!

Anyone know if this is actually possible or are we condemned to all use the same skins/flv players?