Not really odd.... being that Nvidia, until recently had the 8 bit pallet enabled. The full patch won't work if the 8 bit pallet says PASS it must say FAIL. Maybe you weren't using the newest drivers.
Nvidia didn't always get the 8 bit pallet thing right, if it so happened to be a driver where they got it right, then all you would need from the TNT patch is the FF7config.exe file and not to check any of the Nvidia options, and not copy over the new FF7.exe from the patch. However if they got it wrong (the 8 bit pallet was enabled, but broken)...you'ld see the game run, but the backgrounds looked a mess.
The only reason you needed the FF7config.exe file from the TNT patch was because it would allow you to choose the 3d acceleration option. The orginal FF7config.exe that's in the game...does some kind of check that for whatever reason the new cards fail at...so it omits the 3d option from being a selectable thing. Anyway...that's probably the reason why you couldn't get it to work when you had a Nvidia card.... You just didn't know the in's and out's.
Heh...the secondary option was to use Rivatuner in disabling the 8 bit pallet textures, and then you could use the full patch, like you can with the most recent drivers....(until they re-enable them again...then we are back to where we were before...maybe it'll work...maybe it won't)