I was going over SANS and I found this :

We received couple of calls that users are
not able to dial up after applying MS06-025 (KB911280).

I verified this on a test machine and it looks like it breaks dial up.

We have some scripts that need to be run in order to authenticate the user
properly after the dial up connection is established.

It looks like the patch prevents scripts from running at all. Even when I
turned on the terminal window (in interactive logon and scripting) I can't
log in manually at all. After the connection is established I can see the
Username prompt in the terminal window but I can't enter any data.

Uninstalling the patch fixes this."

Here is the MS06-025 Bulletin :

Here is more information on the vulnerability :