blank catalog page

[paellison]

I've had v2.21 running for sometime now. I recently had a brain freeze and changed the file permissions on the catalog/product_thumb.php file to 777 and ran the program direct. Don't ask me why..it was late...anyway, from that point the main catalog page could not be displayed. I attempted to set permissions back to 644 but to no avail. I still get blank screen. The admin module is working normally.

 

Any help would be greatly appreciated.

 

 

 

Thanks in advance.