I have been having the same issues as described. In the crafting window when searching for "s", immediate freeze. Also when scrolling down far enough in the building category, immediate freeze.
Issues happen on both exploration games as well as in the editor. Also occurs on multiplayer games.
My graphics card is an older AMD HD5770, much like the others that have posted one of the HD5xxx or HD6xxx range. Driver update or rollback does not help.
Problem does NOT occur on my wifes' machine, same multiplayer game, which has an AMD HD7850.
Happy holidays, hope you find a solution soon. Or perhaps the Unity update coming in 0.7 helps.