Question : Outlook Web Access 2003-Inbox problem/ Invalid procedure call or argument

We are using OWA  Exchange in my company, since last Tuesday we are facing a problem which is we cannot load the Inbox, Sent messages, Calendar&etc due to the following reason;
Line: 3069
Char:  3
Error: Invalid procedure call or argument.
Code: 0
URL: http://88.85.242.243/exchange/a.dughem/inbox/?Cmd=content
We are using Windows Server 2003, Exchange 2003 & the instaled IE on the servers is IE6. We are using IE7 in the regional offices but our Head office are using Office Outlook 2007 (its working probably). So can you please advise me what is the best salutation of this problem, the cause of it & how to avoid it. Also, we can load everything only on FireFox, Opera & Safari but we cannot Send, Reply or Forward the messages.

Answer : Outlook Web Access 2003-Inbox problem/ Invalid procedure call or argument

Check the security codes, thats all.