Hello, Excuse me if this is not right place to post this is my first post.I'm running Windows server 2003 SP2 and Exchange 2003 SP2I have a user who logs in to OWA from a Mac. When they click on calendar along the left it does not display the calendar on the right it brings up the login page again. All other tabs work fine(i.e. contacts) I can replicate the issue using my PC running IE when I select basic client. It works fine when Premimum client is selected. It works fine with basic client selected with my account instead of theirs.There are two errors in the application log:Faulting application w3wp.exe, version 6.0.3790.3959, faulting module davex.dll, version 6.5.7654.12, fault address 0x00067b3e.Faulting application w3wp.exe, version 6.0.3790.3959, faulting module davex.dll, version 6.5.7654.12, fault address 0x00067b3e.Looks like they are the same error it just happens twice.In the System log there is this error:A process serving application pool 'ExchangeApplicationPool' suffered a fatal communication error with the World Wide Web Publishing Service. The process id was '4168'. The data field contains the error number.I also Ran procmom while re-creating the error. I filtered on PID 4168 it is w3wp.exe process.There are two success entries:Date & Time: 3/25/2010 9:38:24 AMEvent Class: ProcessOperation: Thread CreateResult: SUCCESSPath: TID: 7256Duration: 0.0000000Thread ID: 7096andDate & Time: 3/25/2010 9:38:37 AMEvent Class: File SystemOperation: CreateFileResult: SUCCESSPath: E:\Exchsrvr\exchweb\bin\auth\owalogon.aspTID: 3752Duration: 0.0000264Desired Access: Generic ReadDisposition: OpenOptions: Attributes: REShareMode: Read, Write, DeleteAllocationSize: n/aImpersonating: AACDMAIL\IUSR_AACDMAILOpenResult: OpenedThen there are two buffer overflows: Date & Time: 3/25/2010 9:38:37 AMEvent Class: File SystemOperation: QueryInformationVolumeResult: BUFFER OVERFLOWPath: E:\Exchsrvr\exchweb\bin\auth\owalogon.aspTID: 3752Duration: 0.0000055VolumeCreationTime: 10/6/2006 1:39:32 PMVolumeSerialNumber: 96C9-7BF9SupportsObjects: TrueVolumeLabel: EDRAandDate & Time: 3/25/2010 9:38:37 AMEvent Class: File SystemOperation: QueryAllInformationFileResult: BUFFER OVERFLOWPath: E:\Exchsrvr\exchweb\bin\auth\owalogon.aspTID: 3752Duration: 0.0000052CreationTime: 11/3/2006 11:57:36 AMLastAccessTime: 2/28/2007 1:34:12 PMLastWriteTime: 6/24/2003 2:00:00 AMChangeTime: 3/1/2007 4:18:33 AMFileAttributes: NAllocationSize: 8,192EndOfFile: 5,574NumberOfLinks: 1DeletePending: FalseDirectory: FalseIndexNumber: 0x2000000002d87EaSize: 0Access: Generic ReadPosition: 0Mode: AlignmentRequirement: LongOf course there are a lot more entries after that some of them look like they are related to DrWtsn32.exe It is only this certain user but it is an issue as they cannot get to their calendar from their main machine right now.Thanks for any ideas or answers. Matt