Munging problem whit large map

[Venom]

i try whit a 400x400 map, look the acquaduct and the temple in editor




and look in game after the munge

[Teancum]

your terrain must be a power of 8 -- 64*64, 128*128, 256*256, 512*512, etc. Sucks huh...

[Rends]

This could be a problem of not centered Objects. If you don´t center and freeze them in xsi they will appear out of place in game.
The only solution is to move them in the Zeroeditor until they appear fine in game (could be a painfull work).