The game requires a lot of memory, which causes the flash to crash frequently (White screen with exclamation point). This happens just after you've cleared 30 something waves of ZOMGs and DDTs, and all the time you spent clearing the territory is wasted. This happens to me about every other territory I clear even if the game is the only thing I'm running on my computer.
This isn't really the fault of the developers, but there has got to be some solution so that this doesn't happen to people.