I noticed some slowness in the typing of the recent few messages here as well. The longer the text goes, the slower it happens. (speed at which I see the letters appear on the message text box than the typing). I am using IE8, Vista Ultimate (all with latest updates) and mostly I use the Quick Reply option. I was fearing IE would crash and hence did the Cntl-A, Cntl-C trick - wasn't needed but still...

Could have been some add on those specific previous pages (as am not getting that felt for this message) and the CPU usage had temporarily gone 100%. It's ok now without a crash though.