Short freezes BtS 3.17

[stuge]

My problem is that the game appears to have hiccups. When it's my turn, everything goes smoothly for a minute or two and then the game freezes for about two seconds. Then it runs smoothly again for another couple of minutes before freezing again. This is driving me nuts. I've already re-installed 3.17 once. The glitch didn't occur in 3.13.