#1 unserialize the cache file?

[psodini]

When I go to the flickrViewer.php file in my browser, the window displays "Couldn't unserialize the cache file." Any idea what the problem might be? I'm using SimpleViewer 1.8 and FlickrViewer 1.2.2 ... and nothing is showing up in my gallery after the screen displays the "Loading Gallery" message.
Any help is much appreciated. Thanks!!!
Pam