In the 2.6 series of kernels they introduced a new option to lower the kernel stack size by 4kb. Without getting into details, this is better for some things, but initially some drivers had problems with it (mainly things like the nvidia drivers). Most drivers I've heard of that had problems with this have since been fixed.
Anyway, your going to have to compile a new kernel for you system. The best way to do that is to download the Fedora 2.6.10 kernel package
. This should have all the normal fedora options already in it. Install that rpm. It should be put in the /usr/src directory. Then follow the kernel compile howto from this site and remove the 4k kernel option I described in my first post.