I haven't seen this before... Have you searched the forums for this problem? The only idea that I have is that I wonder if waiting a day will bring it back. When you do a hard reset there are some of the Nokia apps that don't automatically download right away, but all the times I've hard reset my phones, those apps would come back within a day. I've never noticed, though, if the Nokia Collection was part of what wasn't there.
You might also try installing SysApp Pusher and use that to install the Nokia apps like Extras + Info and such that are among the apps I'm referring to above that don't automatically install right away, but install within a day or so.