I got this through Donna (one of my favorite security blogs).
A recent patch, MS06-015, could cause some problems, such as:
• Unable to access special folders like “My Documents” or “My Pictures”. • Microsoft Office applications may stop responding when you attempt to save or open Office files in the “My Documents” folder. • Office files in the “My Documents” folder are not able to open in Microsoft Office. • Opening a file through an application’s File / Open menu causes the program to stop responding . • Typing an address into Internet Explorer’s address bar has no effect. • Right-clicking on a file and selecting Send To has no effect. • Clicking on the plus (+) sign beside a folder in Windows Explorer has no effect. • Some third-party applications stop responding when opening or saving data in the “My Documents” folder.
And then there’s this little mention:
The VERCLSID.EXE process is flagged by Sunbelt Kerio Personal Firewall. Sunbelt Kerio Personal Firewall (http://www.sunbelt-software.com/Kerio.cfm) has a feature which flags any attempt by an application to launch another application for the user’s approval. Kerio is flagging Explorer.exe’s launch of VERCLSID.EXE. When this occurs, VERCLSID.EXE’s execution stops until the user clicks through Kerio’s notification dialog. Users can configure Kerio to allow VERCLSID.EXE to execute without prompting.
Well, it’s nice to be made famous this way, but the resolution is here, in KB918165.