INFO: Update Rollup 4 for Exchange Server 2007 Service Pack 1

"Not aware of many customers being affected" - let's consider who was most likely to be affected: first, the timing of the patch on automatic update meant that it was night or evening in Europe and the Middle East, but still day in North America. Since most would have automatic updates set to go off outside business hours, not so many will have caught the patch in America, but more in time zones east of the Atlantic, and they're less likely to have reached the attention of the Exchange team in the USA. Second the sort of customer using automatic update is likely to be the small to medium size, with a small IT staff or IT contacted out. These people are less likely to have support contracts and less likely to be able to reach the right people at Microsoft. Are you sure it was "not many customers"?