It doesn't matter if it supports it or not. The fact of the matter is it's not working. I doubt RTB has any intention of supporting IE with their web interface because every web developer ever has a seething hatred for IE, so my bet is on that you'll never get a fix. This means you have two options:
- Download a browser that doesn't suck
- Download
FileZillaIf you get FileZilla, fill in the information as dictated by your FTP Access tab under Management on RTB.