No I just downloaded classifieds there is no reference to showgallery.php anywhere in the code.
Are you sure your checking the box to overwrite when you reinstall the new plugin in your vb
Like I said your free to edit any link in the navigation manager of vb
and correct that ONE link that way since you seem to have a problem reinstalling the plugin.
I am using the plugin right here feel free to try all links they do work thats a clean install of 5.0 Main Index - Reeftalk Classifieds