iNotes - Error on Page

I rebooted our Domino server last week. Since then, many users through-out the organisation have been experiencing this problem:

Sometimes, not always, when iNotes has loaded in IE, the ‘Error on page’ icon and message appear on the bottom left of the screen.

The following message is shown:

Permission Denied

Mail/

Code:0

URI: https://mail.carnegiecollege.ac.uk/[user’s mail-file]

Line: 9

Char: 1

The error is affecting many users and seems to be independent of the version of IE.

Has anyone else experienced this? Any ideas?