MS’s Knowledgebase is reporting a few more problems with Office 2007’s first service pack:

You receive an error message when you try to apply any of the 2007 Office Service Pack 1 packages on a computer that is running Windows XP Service Pack 2

You are prompted unexpectedly to restart the computer after you install a 2007 Office service pack or a 2007 Office update

Error message when you try to start Outlook 2007 after you install 2007 Office Suite Service Pack 1: “Outlook.ost is in use and cannot be accessed”

The Document Scanning tool crashes when you use the tool to scan a document after you install 2007 Office Suite Service Pack 1

No word yet on how widespread the problems are. If you get hit by one of these, let us know.