The real players here are the dev team, of course. I sent this tonight in reply to some support emails and hopefully they can narrow it down... the other games have NO LAG, keep that in mind!!
Instead of installing programs I don't want to use, I have some important observations and suggestions about this lag issue.
While debugging Nords I noticed a few very apparent problems. I'm using my 3.0ghz dual core AMD with 4gb memory, latest chrome browser.
#1 - The fps of Nords at rest is all over the place, from 6-15 fps. TD and Sparta are steady 30fps while Soldiers and Stormfall are steady 17fps. This tells me you have too many interrupts in your main program loop.
#2 - The game has the worst problems when loading the Blood Pact and some of the Clan Hall windows, it falls to 1 or less fps!. My Items window works perfectly, Daily Offerings is OK. Compare the code between the bad Blood Pact and Clan Hall windows to the windows that work OK and you'll be well on your way to fixing this problem! No other windows in TD, Sparta, Soldiers or Stormfall have this problem.
#3 - In general, every one of your flash programmers should memorize this article... http://www.adobe.com/devnet/flash/articles/optimizing-flash-performance.html
If you focus in these directions you will SOLVE the lag issue!
Good luck
I would imagine in the middle of all this lag mess they'll find memory problems that cause it to gradually max out and REALLY bring everything to a halt, like 5 second delays in typing in chat. Whatever, they just need to FIX IT.
MOD EDIT: Link Removed. FaZi