IE hitch in the get-along

After updating IE5.5 with MS 5.5 Service pack, now getting an intermittant “pause” when on line. Mouse works (curser moves), but like explorer “freezes” for a short time before it will execute completion of tabbing, or move on to a clicked link, andtask bar and hidden full screen IE menu bar won’t respond (and other stuff). Have upgraded to IE6 since and problem followed. ALSO, Outlook Express is “goofy”. When I click Icon, used to immediately launch Outlook. Now there is a significant pause before Outlook launches and once it finally does, does not immediately “send and recieve” like it used to even tho the options are set to do so. What happened?