Huge permorance difference - Help?!

Greetings,

I've recently started developing a game and i'm currently experiencing a huge drop of framerate when i'm entering "Maximize on play"-mode. My game currently consists of a simple terrain with some free shaders, FXLab's water, a directional light and a first person chamera - nothing that is supposed to take huge amounts of permormance.

I've tried disabling the terrain, the water, the light - and even when the only thing my game consists of is a character controller falling through empty space (everything disabled) my framerate is still around 30 FPS on fullscreen mode.

I tried playing another unity game (Bootcamp Demo) to see if i can simulate the same thing and it didn't happen in that game, so it's something specific to my game.

Here are the FPS's for my game and the bootcamp demo in normal and fullscreen mode:

My game: Normal developing resolution - ~100 FPS Fullscreen 1920x1080 - ~30 FPS

Bootcamp demo: Normal developing resolution - ~75 FPS, Fullscreen 1920x1080 - ~65 FPS,

I also attached two pictures to see more detailed information.

Thanks in advance for your help :-)