i use a wacom intuos draw, but the mouse is still plugged in. U think its conflicting drivers?
I have an intuos too. It's not a pro tablet and it shows but you can still pull off great stuff with it. My drawings are by no means great but I have no problems with lines. First of all, unless it's lagging it's not a tablet issue but one (or both) of these things:
-brush settings
-hand movement
For brush settings, you wanna make sure you got the shape dynamics panel right because if those settings are configured incorrectly the brush will automatically deform your lines even if you've got the calmest hands.
The hand movement is the more probable thing though. Drawing on tablet is different from drawing on paper because here you have to translate your movements to the sensor clearly. I'd suggest avoiding slow long strokes and instead focus on lightning-fast ones. Try pulling a few very fast curves.
Finally, if you want really smooth drawings which are relatively simple in terms of color you shouldn't be using Photoshop at all. Use Illustrator instead as it automatically sharpens all lines with each stylus stroke. You can get perfect lines even if your hand is shaking a lot. Also, it uses vector graphics which is pretty sweet.
Edit: It could also be that you're drawing on a big file from a zoomed out position. You should always zoom in reasonably when pulling lines because that way you're closer to the direct pixels you're working on so the sensor picks up the lines more accurately rather than simply tracking it over a bigger group of pixels and marking them on average since your stroke is less well defined when you zoom out.