The problems are not fixed, but there is a non-endorsed patch which allows you to change your aspect ratio in-game (normally this is fixed) but doesn't forbid you from going online. I tried it, and it actually made my framerate
worse so I suppose it varies with computers. Nevertheless, I'd at least recommend it in case it does work.
The main issue people had was with controls, which are NOT AT ALL optimized for the PC. They're so un-optimized that labels in-game still think you're playing on the XBOX (eg, it'll say "Press A" to accept even though your 'A' key could be something like the T key depending on how you set up your keyboard layout). Me and my friend bought DS for the PC (yes, I have it on both the xbox and PC, sue me
) and initially failed utterly with the PC controls. Nevertheless we continued and still play persistently today. We mastered the terrible controls, to say the least.