Information disappears from Identity Safe

I've noticed on several occasions during the past week that information (username or password) suddenly turns up missing from a login in Norton Identity Safe.  I haven't been able to track it down to something odd that I'm doing... it's just that I select a particular login and nothing happens because one of the two above items has turned up blank.  These are logins that have been there for a few years.  I can key the missing information back in and things are fine until the information goes away a day or so later.

Has anyone else experienced this?