What plugins do you have installed? Some plugins simply don't work on a remote X display. If you have Flash 5 for Linux installed, you must upgrade to Flash 6 in order for it to cause major problems over the network. That link above appears to use lots of Flash, so it would trigger this problem.
http://macromedia.mplug.org Get the Flash 6 package from here.
I guess I'm confused, Flash 6 will help my problems or make them worse?