UIWebView app crashes with Signal "0" when pdf is loaded and some monkey testing is done

I Am using UIWebView to load PDF files. I am coming to the webview from UITableViewController subclass. The PDFs are of good size.

Problem whenever I monkey test the app. It crashes and says:

Program received signal:  “0”.
Data Formatters temporarily unavailable, will re-try after a 'continue'. (Unknown error loading shared library "/Developer/usr/lib/libXcodeDebuggerSupport.dylib")

I understand that Data formater is an error from debuger. But the signal:"0" this is related to memory (I have also seen this signal when terminating from springboard.).

I am putting a break point on view:didRecievedMemoryWarning but he controll never goes there.

some pdfs are too lagre (7.5+ MB). If large PDFs is the problem then please suggest any other way to get those heavy PDFs load well on iphone. Following is code snippet.

    //////////////////// for PDFs //////////////////

        -(void)webViewloadRequest:(NSString *)URLString
        {

            NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:[MY_WebViewController urldecode:content开发者_如何学GoURL]]]; 
            [request setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];
            if(![request isEqual:[NSNull null]])
            [self.myWebView loadRequest:request];
            //[self.myWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:contentURL]]];
        }

    -(void)webViewDidFinishLoad:(UIWebView *)webView
    {
        // finished loading, hide the activity indicator in the status bar
    [webActivityIndicator stopAnimating];
    [self.myWebView.delegate release];  // read this somewhere in SO to retain and release the delegate.

    }

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
    NSLog(@"DOCS ABOUT TO CRASH !!!");
    [self hideModalActivityIndicator];
    UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Memory Warning!" message:@"The file was too large to load.\n So the request is terminated." delegate:self cancelButtonTitle:nil otherButtonTitles:@"ok",nil];
    //[self retain];
    alert.tag=MEMORY_WARNING_ALERT;
    [alert show];
    [alert release];    
    alert = nil;
    // Release any cached data, images, etc. that aren't in use.
}

need Please suggest some way to refresh memory as soon as memory warning is recieved.

THank you