If you see a new inbox message notification and go to your inbox to discover no new message, no message is lost. This is always an issue with the notification flag.This can occur due to the following:
a. page with notification is cached.
click Ctrl r key combination to refresh your browser. If the flag goes away, then you were looking at an old, cached page.
b. missing cookie.
If you are using multiple computers, you will get the flag on each computer. This is because cookies are stored on a per computer basis.
Also if you are in some way deleting myredbook.com cookies, or selectively blocking myredbook.com cookies. This will cause the flag to be set incorrectly.