No, appshopper links doesn't work as well. But when I'm on a developers site and click on the link they provided, it opens itunes. it doesn't go to the clicked link but there isn't an linksnergy message as usual.
New Update: Chrome is working now. I deactivated Anti-Banners in Kapersky. I already deactivated my AntiVirus but it seems Anti Banner stayed active during this. Now that I especially deactivated Anti-Banner, links are now functual in Chrome. Still not with Firefox. And if possible I like to continue using Anti Banner.
Did you install a HOSTS file that contains a list of blocked ad/cookie sites by any chance? You can check by going to c:\windows\system32\drivers\etc\ (Windows XP) and opening the file "hosts" (no file extension) in Notepad. (You may need to enable "show system files" and "show hidden files" in your folder options if you haven't already). See if there's anything there -- in particular linksynergy.com pointing to 127.0.0.1. If there is, remove it.
It seems the problem is solved. I did a reset on Firefox and changed again the setting for itms. I had to chose between Use iTunes (Standard) or Use iTunes. I changed it from Use iTunes to Use iTunes (Standard). After that it worked. Let's see for how long. Last remaining Problem: I still can't use Anti-Banner with Kapersky (which seems to be the source problem. If I activate Anti-Banner I get the linksynergy error. I'll check if google finds me a solution for that. Thanks to all who tried to help me and provided me with tips and ideas. I really appreciated it. Thank you.