uiviewanimationstate release. program crashes randomly

The application crashes very rarely. One time it crashed, and I got the following report:

[UIViewAnimationState release]:message sent to deallocated instance

I am not able to find where is this used. I do not use any animations in my code. What can be the reason for the crash?

this is the code i suspect where it is crashing

-(void)showMessageSend开发者_JS百科ingIndicator
{
    NSAutoreleasePool *pool=[[NSAutoreleasePool alloc]init]; 
    self.av1=[[UIAlertView alloc] initWithTitle:@"Sending Message, please wait..." message:@"" delegate:self cancelButtonTitle:nil otherButtonTitles:nil];
    UIActivityIndicatorView *ActInd=[[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge];
    [ActInd startAnimating];
    [ActInd setFrame:CGRectMake(125, 60, 37, 37)];
    [self.av1 addSubview:ActInd];
    [self.av1 show];
    [pool release];
    return; 
}

---

Firstly, you are setting av1 to a retained object. Replace this line with something like this:

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Sending Message, please wait..." message:@"" delegate:self cancelButtonTitle:nil otherButtonTitles:nil];

self.av1 = alert;

[alert release];

Secondly, you never release ActInd. Add [ActInd release] before [pool release]. This is safe because av1 retains it when you call addSubview:

On a side node, why the NSAutoreleasePool? You typically need those on a separate thread, but showing an activity indicator should be done on the main thread.

And also, if you want to follow any conventions, you should replace ActInd with actInd.