Links to other threads etc. automatically logout anybody who clicks on them

The problem is quite simple: Clicking on any link to another post, forum, ... logs the user out because it does not contain the sid of the clicking user.

I did not report this as "Bug" because it might be by design or even a problem in the whole authentication design. Whatever it is, it is annoying not to be able to link to other posts without causing problems to anyone clicking on the link. I tested it on vB and it works without problems, so it seems to be possible to implement working interlinks somehow.