Make absolutely sure that you have set the card for your 6581. It also houses an 6850, but this must be set with a jumper.
On the info sheet that comes with the card, it says:
Only set the 8581 jumper if the real 6581 is installed! It must be left open with 8580 or 6582 chips. This jumper applies 12V to the sockets which are needed for the 6581, but it could destroy any other version of the SID.
If you're giving a 6581 too little voltage or another chip too much, that would explain your problems. It may be that chipless CW3 ship with the 12V off by default, so not to damage a wrongly chosen chip. Check it out.
3) Is there anything that supports the joyports?
Windows does not have any drivers yet - only Amithlon or Pegasos, at the moment. But UAE will also support them directly.
I'm jealous about you being able to install the driver - on my Linux setup the catweasel drivers just point blank refuse to compile (typical linux behaviour: fail for no apparent reason and then never explain why). So I haven't yet heard the SID and maybe never will. :-(
