Calendar Reminders stops popping up after number of days

Hi all-
I'm curious to know if others have run into this or not. We've been observing calendar reminders disappearing after being snoozed for a while or after several days. Usually a logout and login occurs between the snooze and/or the several days. This is quite difficult to deal with because missing reminders causes issues with missing events (like paying bills). Has anyone else observed this? Are there some restrictions or limitations with the reminder system defined anywhere and I just haven't come across it yet?

Thanks for any assistance,

John