It appears that if a system contains an obsoleted package, RHN Website would not lits it as an outdate package and would not count it as an outdated package (and might show the system as fully updated). To reproduce: create a fully-updated Limbo system and then replace redhat-config-date with dateconfig (and run up2date -p, obviously). RHN appears to think the system is still fully updated, but it's wrong. P.S. up2date hanldes this correctly, only RHN Web site gets it wrong.
chip will need to figure this one out.
This bug has been closed due to inactivity. Please open a new bug with specific details if this problem is still occurring or if an enhancement is needed.