I am having similar issues like the post event 1003. I have Microsoft Windows Server 2003 R2 Enterprise x64 edt service pack 2 with exchange 2007--hub transport role installed and the system keeps crashing unexpectedly. I noticed that someone reviewed the dump files and found the culprit. However, when I view the dump files it shows a different file causing the problem and most of them point back to Microsoft. I have attached most recent dump files. Please review and help me solve this issue! It is happening very frequently and email traffic is stopped each time. Thanks in advance!