I am sure that you are aware that statcounter.com has a very high pr. I made two posts on the forum and already my profile is pr3! I have a link to my site on it. Will google consider it a backlink?
your profile page has a high pr because it is just a subpage of statcounter. That's what I thought >_<
Yes it counts, but if their page is similar to the one here at DP the only reason you have a PR profile is because you just happened to be online when the update snapshot happened. Your profile's PR will go up or down dependant upon whether or not you happen to be around on the next update snapshot (which should actually be happening sometime rather soon). You should/could stay logged in there (and here for that matter) and if they allow live links in signatures try to limit your posts to high quality, or high traffic threads (like I talk about here) and you'll find the click through rates for it match the quality of your profile PR
have you check that there is nofollow or not? and are your profile and your signatures are visible for the search engine bots?