Tried to mass delete about 76 stale rhn profiles in the qa test
account.  Got the following:

500 Error - Internal Server Error

You may have reached this page in one of the following ways:

   1. You are using an outdated version of Konqueror 3.0, which may
not handle form variables properly in all cases. Continuing to use
this outdated version of Konqueror may have unexpected results. Please
up2date to the latest version of Konqueror (3.03 or greater), or if
this is not possible, please use another browser.
   2. You've found an error in our site. Please help us by sending an
email to rhn-feedback@redhat.com with details of how you received this
message.
   3. You've done something naughty. Stop it.


Specific steps that I took:
1. used the search feature to find machines that had not checked in in
the last 180 days (about 76 machines).
2. selected all of these machines and hit the "Manage" button
3. viewed system list in SSM
4. viewed the misc menu in SSM
5. viewed the channels menu in SSM
6. went back to the SSM - Overview page and clicked the delete link
7. after reviewing the list (hit forward once) confirmed deletion
8. the page took a long time to load and then showed this error.