Automounts: All mounting and will not umount on its own

Now I will ask a question I wanted to comment on but did not have the reputation points (I am a new user) to comment:

I have a few SLES 11.2 servers. They do something really strange with automount. We have nearly 500 possible automounts our users and their codes may need, including automount entries for each user's $HOME. No problem. If I visit any one of the thousands of Linux workstations or servers we support, I may see 10-20 automounts. And they unmount as expected.

But, we think since going to SLES 11.2 and KDE4, though we could be wrong, we have a few systems, noticeably one of the head-nodes on an HPCE Linux cluster, that has ALL 500 automounts alive and mounted... And they do not unmount on their own??? But, we can run a script to manually umount them and all but the few that are really active, unmount without complaint?

I wonder if it is some glitch in the nightly tape backup program? Maybe it wakes all the automounts but does not back them up? But why do they stay up?