My suggestion: make sure that -- at least -- version 12.2 (current as of this moment) of the AMD driver is being distributed on the Lisa/Gnome .iso.
There is strong suspicion of a conflict between previous AMD/ATI drivers, certain AMD/ATI graphics chipsets, and Gnome3. An Internet search shows many problems related to this combination. In my case, another Lisa version without Gnome3 (LXDE) boots straight-away, to a fully-functional live system.
If there are different builds of Gnome3 in circulation, that may also add to the problem. This I don't know, and is a question best answered by others in the Mint community with more knowledge than I have.
I see 12.1 was "supposed to have fixed" known incompatibilities along these lines, but I see no reports that it actually did. I would expect not, since 12.2 followed rather soon. If the Gnome/Lisa .iso currently in distribution contains drivers in the 11.xx series, likely it will give lots of folks problems, if they have the 'right' chipset to set this off.
It would be doing a service to Mint's reputation to prominently post somewhere (or is it already there?) that users with ATI/AMD chipsets, who have a Lisa/Gnome3 .iso that verifies but won't work, should just go directly to a Gnome3-free Mint version.
Continuing to burn one disc after another, hoping the next will work ... won't.





