Frame Rate Issues

Hi all,
I'm working on a project that uses the Tutorial 9 code and involves very fast physics motion. I have an object sliding down a track, and that runs perfectly, but for some reason when i add a medium sized plane with a 512x512 texture in the distance (as one side of a skybox) the frame rate will slow way down intermittently. When I turn off mipmapping on the plane's texture the slow downs are less frequent, but they still occur enough to cause issues. Any idea why the addition of a single plane would be causing this to happen?

Thanks a bunch!

That's really a good question, It shouldn't slow down at all... iPhone can handle ALOT more than that hehehe

Maybe send me the .blend to check if everything is exported and managed correctly...

Cheers,