I took a good look at your problem and I couldn't find the issue. After looking over all of the code, line by line, I did not see how it could mess with the sessions of two separate applications on different servers.
I then tested to see what the response speed was like from the bar host. Pretty fast; nothing slow about it. Then I put it in a web page and it loaded up just as quickly.
Next I put the bar into a sample forum skin to see it live... worked like a charm. Nothing slowed down and who's online was still displaying the proper location. You can see it here:
http://www.vbmechanic.com/skins/index.php?styleid=7
Sorry, but I don't see how it is slow or affecting sessions at all. Granted, the board only has 9 people on it at the moment, but it shouldn't make that much difference.