We were integrating a 3rd party product’s web parts with MOSS the other day and came accross an interesting problem. In site editing mode, all the drop down menus would appear for a flash and then go blank. The actual admin pages we were trying to get to would work if you entered them into the browser directly, but that isn’t an easy way to manage the site!
The problem turned out to be that in the process of getting the 3rd party web parts to work, the support team had added a MIME type to the IIS installation.
This is obviously not what you’d do in a production environment, but the support team put it in to rule out the MIME type in the integration problems. Once the rogue “catch all” MIME type was changed to a more specific extension, and of course the arbitrary IISReset.exe was performed, the menu’s came back to life.
The relating MS KB article is support.microsoft.com/kb/939311/en-us