At 2pm PST we started receiving reports that some customers were
unable to log in to some apps.
We were not able to reproduce this ourselves but we reverted the
OpenID servers to a previous state and that seems to have resolved the
issue.
As of 2:53 PST we believe the problem has been resolved.
If your customers are still having problems accessing your
application, please add a comment to this issue:
http://code.google.com/a/google.com/p/apps-api-issues/issues/detail?id=2798
/Rufus