I have a Dell studio 1555 with an ATI Mobility Radeon HD 4500, and I have installed the proprietary driver but when I go to settings>details>graphics, ubuntu tells me the driver is VESA:M92, experience: standard.
The driver has definitely installed correctly as I can get up the catalyst control centre and change settings which effect what I see. So is this just a false indication or am I not getting the full experience out of my video card?
Try running the following command in terminal (Ctrl + Alt + T):
I think it will show you that you are using the correct driver and so if you go to Settings → Details → Graphics and you see the VESA:M92 driver, it is just an incorrect indication for a reason that I do not know, but I have the same issue here on my laptop.
Hope this helps.