dotnetnuke: links to external files not working
===

We currently are running DotNetNuke 4.0.6. On the portals there are links that we have created to access files located on fileshares. When we set them up and save the page, then when we click that link nothing happens. 

I have currently set the link up like this:
Link Type - URL
Protocol - Other
URL - file://///myfileshare/filesharename/folder1/folder2/myitem.pdf

If I select anything else (http, https, ftp) it doesn't work. When I mouse over the link it looks to be rendering correctly. 

Can anyone help with why this may be happening? Am I missing a setting or selecting the wrong item? 
