That's a Linux-specific problem; on other OS'es uname -r returns the main OS release number, and not the patch level (which is returned by -v). eg:
OS -s -r -v
AIX 5L/ia64 5.1 AIX 1 5 Linux 2.6.10/x86_64 Linux 2.6.10-5-amd64-k8 "#1 Tue Apr 5 12:10:43 UTC 2005" MaxOS X Darwin 7.9.0 "Darwin Kernel Version 7.9.0: Wed Mar 30 20:11:17 PST 2005; root:xnu/xnu-517.12.7.obj~1/RELEASE_PPC" Solaris 8 SunOS 5.8 Generic_108528-06 Solaris 10 (unpatched) SunOS 5.10 Generic