Media Manager Permalink Edit problem

I’m finding it impossible to change the root url of the permalink of an image in media manager’s edit media window.
If I try to paste a new url it strips out all the colons and slashes :// making the link a run-together mish-mosh. Everything is forced to the root site url. I no longer have the ability to link outside the site.

This is unacceptable. I’m using a static image placeholder inside a slideshow for a video clip hosted elsewhere – any click on the image in the slideshow needs to directly load the video link. Older images (before 3.5) still work fine because this was allowed.