The obvious thing is to not go back to those two sites until you resolve your
problem. Since both sites are Flash oriented I would check other Flash sites and
see if you can duplicate the problem. If it seems to be Flash that is the
culprit, then I would re-install Flash. If you suspect Firefox check out the
same sites with another browser. If Flash works there then copy the Flash files
directly from the settings folder that works to the one that doesn't. Flash can
be found in your hidden folder .mozilla/plugins and a similar folder for other
browsers such as Flock. There are two files to copy named: flashplayer.xpt and
libflashplayer.so.