It seems that sometimes is frame rate lowered in game. During this, game is "snatchy". (I don't know if it is the right word).
It is random, I didn't observe some reasons. I start a new game, playing without problems and in random time the game goes to "snatchy", as though frame rate in game is lowered. If I save game and load the same, the problems is there again immediately. If I load another game which hasn't this problems, it is correct. So this problem isn't in whole patch, but only in some reasons in game (too many trains? buses? plant? trees?, I don't know...

I using TTDpatch 2.5 beta 5 (r352; May 28, 2006).
I tried this in two computers (both 512MB RAM, procesor 1800MHz) and in both is the same problem.
In attachement is my saved game, newgrfw.cfg and ttdpatch.cfg where is the problem.