The GTS250 is yet another rebadged G92, but nonetheless it is nice that Netkas package allows it too to work.
Interestingly, the Nvidia "helper" card can NOT be another G92 EFI card, causes a no boot scene.
By using a G70 helper I got it to boot.
The GTS250 is QUITE a bit faster than 8800GT, if only someone really clever would help me on the Nvidia EFI ROM sewing project...........
I have tried countless times to get my EVGA GTS 250 512mb to work with 10.5.7 (iDeneb) and haven't gotten it to work.
This (http://aquamac.proboards.com/index.cgi?board=osx86driversandkexts&action=display&thread=838) finally worked for me, but without Quartz Extreme. Now I can't even use to that method anymore, I get the "Please restart your computer" screen over and over.
Can you please tell me how you got your GTS250 to work with Leopard?