Are you by any chance using Avast? If you are, I have something that might help fix the problem. I have this problem, and yet have found a permanent way to fix it without having to go through the following each time I come into the room.
Right click on Avast in your system tray, go to "avast! shields control", there is a secondary list that will appear as soon as your mouse pointer selects it. There are 5 selections, but only 4 available: Shields are on; Disable for 10 minutes; Disable for 1 hour;, Disable until computer is restarted; Disable permanently. Choose Disable for 10 minutes, there will be a pop up asking you if you are sure you want to do this, the No will have timer counting down from 50 seconds, but you will click on the Yes button. You will have to reload the chat room, but once you do that, go back to the beginning and when you get back into the Disable section, you will see at the top of the list is now available to be clicked, Enable all shields (number of shields that are off). Click on that and it will restart all shields and you shouldn't have any lag issues until you leave and return to the room.
Hopefully this will fix this issue for you, though I would love to have a more permanent fix, this only happened after Avast upgraded a couple of months ago and since then I have been having to do this each and every time I go into the room.
-huggggggggggggles-