Running slower the longer the game goes on is definitely normal.  In fact I'm assuming you're not on a large map if you made it to 800 turns before out of memory errors made it unbearable.

The siege thing I don't know, I've never used the siege function and was only vaguely aware it existed.  I don't even know what it does or why you would use it.

Well, I play a game rigth now and turn 1000 + on a large map and dont have the OOM (out of memory) or the leek of memory crash, it's more stable than before. I'm playing this game on the first 1.09 patch, not he 1.09E.

It's maybe my fault I had a game save at 1.09 the 1.09e came out still use the same game the game is on a large map . In 1.09 I was haveing my game freeze up quite abit. Not so much after the fix but the game booged done alot when I zoomed out to the cloth map otherwise all units moved fine. I wiped out the first group totally ( I only have 2 enemies )thats where it started it was thier last city the option was do you want to siege ( I had to research siege) I said yes . After my victory I tried to move my units off it would not let me because it said I had to quit the siege before I moved I can move all my units except my leader who is stuck there. The game is good I do agree with everyone it has loads of potentila just needs alot more love is all. That being said unlesss anyone has any ideas on how to fix the problem I will have to restart Oh and doing the saved game thing well got lazy after a while was having to much fun and forgot to save so I would have to go back too far .