The Exchange backups fail intermittently with 0x8000FFFF errors when opening
the IDataSource2 interface object.  There are absolutely no errors in the
Event Viewer during this time frame.  The error has occurred ever since they
upgraded to Exchange 2003, and occurs about once in a week or two. It cannot
be reproduced at will. The customer confirms that the Storage Group has not
been renamed.

This is a log from our backup application:

Thu Mar 15 00:21:16 2007 SNBFBR4951E 4464: getObject: Error from
IDataSource2::Open(), rc = 8000FFFF

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464: E2CDOServer::getExchangeServer:
Error from getObject(), rc = -4

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464: E2CDOServer::getSGNames: Error
from E2CDOServer::getExchangeServer(), rc = -2

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464: E2CDOServer::findStorageGroup:
Error from E2CDOServer::getSGNames(), rc = -1

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464:
E2CDOServer::getStorageGroupSchema: Error from
E2CDOServer::findStorageGroup(), rc = -2

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464: E2InstanceReader::read: Error
from E2CDOServer::getStorageGroupSchema(), rc = -2

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464: E2ObjectInstance::backup_read:
Error from E2InstanceReader::read(), rc = -10

Thu Mar 15 00:21:16 2007 SNBFBR4950E 4464: E2Session::backup_read: Error
from E2BackState::read(), rc = -1

You can see that the getObject() method fails with a 8000FFFF error which
seems to be a generic “Unexpected Error” according to the KB articles.

The call that fails is

 hr = dsrc->Open(wcbuf,
                    NULL,
                    adModeUnknown,
                    adFailIfNotExists,
                    adOpenSource,
                    NULL,
                    NULL);

Where dsrc is an iDatasource2 object.

Any Ideas why???