I know this is a little old already, but since today seems to be my getting-up-to-date-on-ahfm-threads day, i'll just leave my 2 cents here now anyway.
First, having zero Guests doesn't mean they all just went and registered. Some certainly just off and left.
But then again he didn't say that.
The biggest difference: Instead of few members and many guests there were suddenly more members and 0!! guests in the forums- for sure if you can't view without log-in/being registered!
Second, while maybe nice in theory, it's actually a pain in the a** to try and track or restrict people based on IP Adress or Cookies only.
Cookies are a sneeze to remove (good thing) and IP's change on reconnect for most dial-up users.
How about you get say ten views of the forum, just to show you what goes on in there.
SO my suggestion if the d/l links should be members only (is what firefox_muc already suggested).
I think it's quite obvious. vBulletin is PHP code only, if you have a license you have the code. If you have the code you can
hack it any way you like™.
Even easier the feature is already in vBulletin, in a way. You can see these pesky "You need to login to view this attachement" things all over the net on vB Forums.
Easiest solution of course, make the d/l links attachements and lock them for visitors.
Not my favourite, I'd need to download attachements with links just to get the links.
So my thought would be to modify the board a little and have special download links, that you can see as a user but would say "(Please?) Log in to see the Download Link" to lurkin' anonymouse.
On a side note, I also agree with firefox_muc on the other stuff.
These naggin "You don't have the latest version of flash, go download now" are annoying (in general) and most always wrong. If it won't let me see the flash I block the element.
And those yellow information bars trying to bring some "IE experience" to my Firefox are almost as annoying. Sorry to say, but that's so yesterday
Anyway that's my general opinion. I forgive all those little things on afterhours