The KiCad lastest version (2007-07-09) needs at least wxGTK-2.7.1 and I should want to package this release for FC-6. So, I'll be happy if you agree to package a such release for FC-6.
Every updated release of wxGTK brings up new and exciting bugs in various programs that use it. I'd really like to avoid going out of the 2.6.x series on FC-6. However, Fedora 7 and newer have wxGTK 2.8.x, which sounds like it'll work for what you need. I know it's nice to not neglect the older releases, but we have to balance that with the possible downsides.
I understand the problem and respect your position. Is wxGTK 2.8.x in FC-6 possible? Do you have a try?
It might be possible. But it is NOT recommended for FC-6 as it will break many packages which reply on wxgtk. Not to say, many users will have yum dependencies errors. If it break many packages, one should build compat-wxgtk-26 ! I suggest kicad to be updated on F-7 and onwards.