I want to confirm the following assumptions I have about the kernel version numbers obtained with 'uname -r'
That, with each release, the version is 2.6.x-<blah-blah-blah> where x is fixed for a given release. For instance SL5.x is always 2.6.18 while SL6.x is always 2.6.32. The series of numbers that follow the hyphen is some other beastie that is part of the distro and not the original kernel version that Linus releases.