Authenticated SharePoint 2010 in IE10 (Win8) but authentication isn't passed on to SharePoint Designer 2010. Worked fine with IE8 and IE9

Hi guys.

I've recenctly moved to Windows 8 but I'm having a problem connecting to our BPOS hosted SharePoint enviroment (Form based)  in SharePoint Designer 2010.

I use to authenticate in IE8, and then open up SPD and select the SharePoint site I wanted to connect to. However, in IE10, it doesn't do this, it doesn't connect.

Any ideas on what the problem would be and how I could fix it?