NSTimer scheduledTimerWithTimeInterval:target:selector:userInfo:repeats doesn't invoke the method

The timer never invokes the method. What am I doing wrong ? This is the code:

NSTimer *manualOverlayTimer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(hideManual) userInfo:nil repeats:NO];

method:

-(void)hideManual

thanks