UPDATE The Google Apps Status Dashboard reports the problem as resolved at 1:10 pm.
UPDATE Google support advises that this is a problem affecting all domains they serve including Gmail. It has not yet appeared on the Google Apps Status Dashboard.
UPDATE Although 6 tests in a row at 12:00 were all successful, we see some failure and slowness in further testing.
UPDATE Normal service resumed at 12:00.
Starting at about 11:40 connections to LionMail web mail are not always successful. When a connection is made response is slow. Calendar still works normally, and IMAP connections to LionMail work normally.