Are you, by any chance using an HD screen? I don't have any problem with my resolution on my computer display set to 1920X1080. My impression is that Camtasia doesn't handle the HD resolutions all that well. But of course I can't test it out.
I just upgraded to a Surface Pro and the Toolbar Icons are MICROSCOPIC (looked much better on my old Lenovo)!! Has anyone figured out a fix for the Icon size? I hate to lower my screen resolution (if that would work)