Not able to place player start below certain position in world coordinates

Hi

When i am placing my player start within my level, if i place it below 21633.0 cm in world space i get a BADsize error even though there is nothing even possible that it could be colliding with as it is in mid air. I have tried various method such as deleting the landscape and reapplying it but this issue still persisted.
I have thought that it might be an issue to do with the landscape collisions as if i place the player start above 21633.0 cm, the player spawns and falls until it hit the 21633.0 point where the player is then able to walk around on this level. But i am not sure if this is possible to check in anyway?

Thank you in advanced

Check out World Settings and see what KillZ is set to. Also try it again disabling Enable World Bounds Checks.

I have just tried both of these and the issue still persists! Changed the kill z to a larger number and then disabled the world bounds check and it still happens :confused:
Any other ideas or thoughts?

Thank you