Hi guys,About 4 days ago, we started experiencing problems with our Exchange 2003 (SP2) that's sitting on our SBS 2003. Small network, only 4 client machines, all using Outlook 2003. The problem manifested such that when you click send/receive (or outlook syncs with Exchange automatically), it simply hangs, and you get a warning "Outlook is trying to retrieve data from the server" with an exclamation mark". Usually it lasts for about 20-30 minutes and then it either gives up, or it actually syncs, but upon even trying to read the message, or click to view contents of a folder, it hangs again. The problem occasionally does go away for an hour or so (although I can't find the pattern when/why), but it comes back. And OWA is never accessible, logging in takes ages, and if it does log you in, it will hang as soon as you click on some folder or try to read the message. Sometimes, strangely, one Outlook will be all right, whilst Outlook on a different machine hangs and vice versa.I've tracked down the problem in the Event Log - there is a fault with Default Offline Address Book, and it's incorporation with Global Address Book, which kicks off every morning at 5:00 AM. The events are logged as follows:1.Time: 05:36:35 Source: MSExchangeSA EventID: 9331OALGen encountered error 8004011b (internal ID 5020114) accessing the public folder store while generating the offline address list for address list '\Global Address List'.- Default Offline Address List2.Time: 05:36:35 Source: MSExchangeSA EventID: 9360OALGen encountered an error while generating the changes.oab file for version 2 and 3 differential downloads of address list '\Global Address List'. The offline address list has not been updated so clients will not be able to download the current set of changes. Check other logged events to find the cause of this error.If the cause of the problem was intentional or cannot be resolved, OALGen can be forced to post a full offline address list by creating the DWORD registry key 'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeSA\Parameters\OAL post full if diff fails' and setting it to 1 on this server. When OALGen next generates the offline address list, clients will perform a full OAB download. After that time, the registry key should be removed to prevent further full downloads.- Default Offline Address List3. Time: 06:00:48 Source: MSExchangeSA EventID: 1031One of the System Attendant's task is blocked.Function: COffLineABGenTask::WorkThen repeated (1), (2) and (1) again.So far, I have tried the following:1) Restoring a backup from about a week ago, when everything was sweet and dandy - worked fine for the rest of that day, but next morning at 5:39-ish, error events log again, and when came back at work, same problem2) Solution suggested onhttp://support.microsoft.com/kb/922255I added the registry key in, not a lot has changed, except getting a slightly different log for a warning when Offline Address List is updated:Source: MSExchangeSA EventID: 9116OALGen encountered an error while generating the changes.oab file for differential downloads of address list '\Global Address List'. Clients will not be able to incrementally update to the new version of the offline address list, they will perform a full download instead. This is normal if this is the first time this offline address list has been generated. Check other logged events to see if this is a serious error.- Default Offline Address List3) Deleting the Global Offline Address List, created a new one, assigned it, rebuilt it, nothing.4) Removed "Download offline address book" from the Outlook's Send/Receive settings, nothing.All suggestions appreciated.Cheers

Hi, Increase diagnostics logging on the oalgen to maximum and try to generate the oal - this should tell you what the problem is. Leif