I have made sure mobile fog is set to true in the UDKEngine.ini, even for iPad, still it's not showing either in editor or PIE but height fog and exponential height fog actors are working fine.

I would just use those but I was told they aren't compatible with mobile and hence why there is a special mobile fog. Do you guys know of anywhere else in the inis or editor that i might need to make sure this feature is enabled, or perhaps it's my version of UDK? (i'm running on March 2011)