WAD files problems

Hi.

All the WAD files I've tried have major issues with Dolphin. My PC: i7 2600 with GTX 560 Ti

Examples:
Sonic The Hedgehog series have major audio lag when loading and the picture is like 2 fps (so it's unplayable)

Nintendo games like original mario classic have perfect sound, but black picture.

I experimented with External Frame Buffer without luck.

Today I've tried Mega Man 10 and it's the only one that's working without glitches.

Any possible fix in the future?

Cheers