We haven't seen this one ourselves but thought it may crop up :
http://support.microsoft.com/kb/937625 - Error message when you use Outlook to open an e-mail message that contains a PDF attachment from an external mail system: "There was an error opening this document. The file is damaged and could not be repaired"
http://support.microsoft.com/kb/937028 - The Microsoft Firewall service does not start after an ISA Server 2004 SP3 installation fails
We reckon that you should keep an eye because they seem very likley to happen.