QLPreviewController not working in iOS 6

In iOS 6 the QLPreviewController no longer loads a PDF from a URL. It works fine in iOS 5. I have implemented the QLPreviewControllerDataSource methods as documented here.

#pragma mark - QLPreviewControllerDataSource
- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller {
    return 1;
}

- (id <QLPreviewItem>) previewController: (QLPreviewController *) controller previewItemAtIndex: (NSInteger) index;
{
    NSURL *fileURL = [NSURL URLWithString:@"http://www.bliley.net/XTAL/PDF_Instructions/Test_File.pdf"];
    return fileURL;
}

This works perfectly in iOS 5, however in iOS 6 the console outputs:

Couldn't issue file extension for path: /XTAL/PDF_Instructions/Test_File.pdf

I downloaded the file from remote url and saved locally, then I display the PDF using the QLPreviewController .In iOS 6 its working.

First i saved the file from remote url using the following code :

    NSString *local_location;

    NSString *path = [[NSBundle mainBundle] pathForResource:@"sampleData" ofType:@"plist"];
        path = NSTemporaryDirectory();
    local_location= [path stringByAppendingPathComponent:[NSString stringWithFormat:@"My_Invoice.pdf"]];
ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:[NSURL URLWithString: remoteurl]];
        [request setDownloadDestinationPath:local_location];
        [request startSynchronous];

For showing the Pdf :

QLPreviewController* preview = [[QLPreviewController alloc] init];
        preview.dataSource = self;
        [self presentModalViewController:preview animated:YES];

QLPreviewController delegate methods are :

- (NSInteger) numberOfPreviewItemsInPreviewController: (QLPreviewController *) controller
{
    return 1;
}

- (id <QLPreviewItem>)previewController:(QLPreviewController *)controller previewItemAtIndex:(NSInteger)index
{

    return [NSURL fileURLWithPath:local_location];


}