I had a customer call today that had several users trying to activate IRM using the LiveID/Passport Service. It would go through the regular UI, and then come to a grey screen and hang. I took a wild guess, and got a network trace to see if the UI was actually an embedded website...sure enough.
The site is: https://certification.drm.microsoft.com/passcb/clientmain.aspx
Whenever the customer would try to access this from his browser it would redirect him to https://certification.drm.microsoft.com/passcb/default.aspx?ERRMSG=SITEEXCEPTION
which was...wait for it....wait for it...
...a blank grey screen.
So after pulling out my hair for a little while without access to the LiveID servers to see what was happening, I talked to Tamara (a PG member) who suggested deleting all of the cookies/Internet Cache etc.
Had customer close everything, then use the Internet Explorer Control Panel Applet to clear the Temporary Internet Files and Cookies.
Wallah!! Problem solved.
Hope this helps someone running into the blank grey stare of failure someday.