Would someone be able to help me with emulators?

[AntiSocialGeoff]

I got a downgrader that downgraded my version to 1.5. It worked fine. I downloaded the Genesis emulator and I can see the icon and run it.. but after the loading screen it says "Game cannot be played" and some string of numbers.. I really want to play some Genesis games on my PSP so help would be really appreciated.

[AntiSocialGeoff]

I read the tutorial.. and I got my Genesis rom working.. but it moves INSANELY slow.. any tips?

[PSP_Newbie]

well, first i would use DGen if you arent already, as it appears to be the only one still updated and kept up, and i would fiddle around w/ settings as described in a readme?
and im sure there are threads for tips to increase speed.
i remember using the genensis emulator mebe 1-2 months ago and found it very fast