Can you please provide us with the below specifications
McAfee versions :
McAfee security center
McAfee Virus scan :
As a follow up, it does seem to be better today, with the slowdown only occurring after making opening a new conversation and clearing itself eventually. Perhaps today's update help. Yeesterday I had to kill IM to get rid of the mcshield cycles.
Sounds great !!! Keep monitoring and let us know if any issues