I am using Microsoft® Office Outlook® Web Access for Exchange Server 2003
through Internet Explorer 7.  I keep getting the following error pop-up
window when trying to setup a new appointment and check my colleague
attendees availability through the "Availability" tab:

the download of the specified resource has failed. -8

After the error, their calendar availability does not display, instead
replaced with a bunch of slashes as such: "\\\\\\".  Sometimes, the server
re-prompts me for my UserId and Password, which I don't understand because I
already logged into my IMAP email account.

I circumvented this error once by un-installing IE 7 and re-installing;
however, the error has re-surfaced again.

Any suggestions or resolutions are greatly appreciated.