The DSF Strings Expansion pack link here in the US for some people also wasn't showing up - there are some other threads about that out there.
Cakewalk has acknowledged that they have some sort of issue there that they are working on.
I found instant satisfaction through a phone call - they quickly generated a download link for me while I was on the phone and sent the email to me. The whole call took less than 10 minutes - probably closer to 5.
Also, Dim Pro in X2 is still version 1.5, so if 1.5 is installed already then there is no need to install it again.
Hope that helps,
Bob Bone