UIModalTransitionStyleFlipHorizontal laggy

i have just finally registered for a developer account on apple, and have my device set up to run the apps im making. Im running IOS 5 beta 3, and xCode 4.2. On the IOS 5 simulator the flips run pretty smooth, but on the device they run laggy. I am using a lot of NSTimers, but they are all being released..Here is what my code looks like to switch views

HowToPlay *LetsPlay = [[HowToPlay all开发者_C百科oc] initWithNibName:@"HowToPlay" bundle:nil];

LetsPlay.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:LetsPlay animated:YES];

[LetsPlay release];

Anything in their that could cause lag? or anything i could do to fix it? Im thinking this could just be a IOS 5 bug kinda thing, because my iPhone 4 doesnt run the best with IOS 5.

Thanks

It has nothing to do with your code I don't think. I am also running the beta 3 and my application which uses the same code runs smooth. Maybe try releasing the NSTimers as soon as they are done just to see if that is the reason. Or try making a new app and just have it flip and see if that is also laggy on your device.