Some emulator problems.

[Bahamut ZERO]

I don't get what's going on here.
I am trying to play Sonic Adventure 2.
I used 4 emulators to play this game.
When played with Nulldc1.0.3 (one that I got from this site), Chankast 0.25, and Nulldc 1.6 beta I get these graphic problems when I play the levels when colors just block the screen completely.
When played with Nulldc1.0.3 (I got this one from megaupload) I no longer have the graphic problems but the game is running at 7-10 fps. With all these emulators I have a problem where the voices are choppy and slow, not the background music (except with 2nd nulldc1.0.3,the whole thing is slowed down, including background music).
My computer specs are...
CPU: Pentium 4 1.6Ghz
OS: Windows XP build 2600 (one without the updates)
RAM: 786 MB
GPU: Nvidia GeForce FX 5200.
I am told that my gpu is ok, and the cpu meets the requirements so what is going wrong? Please help me.

[FatTrucker]

More likely that your processor and Ram aren't up to it. a 1.6Ghz P4 and 768Mb of Ram is pretty borderline for running emulators of more modern systems like a Dreamcast. As you've been told your Graphics card should be fine though.

[Bahamut ZERO]

More likely that your processor and Ram aren't up to it. a 1.6Ghz P4 and 768Mb of Ram is pretty borderline for running emulators of more modern systems like a Dreamcast. As you've been told your Graphics card should be fine though.

I just did some researching and found out my problem WAS the video card. It seems that when playing with a Nvidia FX it's common to see a polygon was just blocking your view. This happens specifically in Sonic Adventure 2. But since my second nullDC played with no of those glitches, I will have to find a way to speed it up.

[FatTrucker]

Not had a prob with Nvidia hardware and DC emulation. Your speed issues though are almost certainly due to your PC spec.