(PC, WinXP,IE8) I always open the threads with 'Open in new tab' and lately these open and then do a re-'connecting' and start over. The entire thread is then also marked as 'read'.
I don't know if this is related - today, the tab keeps 'jumping up and down' with the following trying to load over and over:
http://static.ak.fbcnd.net/connect/x....php?version=0... (I think this is correct since it just flashes.)
If I have two tabs open to PR, both of my cores are at 100%. If many are open, things come to a stand still.
Terry