Trap freeze and nade freeze.
This is listed in known issues as resolved, but is still happening to me.
It seems that only wire traps cause the game to freeze. Other traps are fine.
Grenades freeze sometimes, but not all times. Might be related to if a structure is destroyed but I don't think so.
I am on an HP Elitebook with Windows 7 Professional.
Using Latest Chrome Browser and Latest Flash.
Intel 2.6GHz CPU, 64 Bit OS
Intel HD Graphics Family video card