I've been on the receiving end of this problem (Kramer The Duke, I'm still trying to get rid of it).
Short answer, you can't use rounds with it. Whether anything else actually works I am not certain.
I ran across this by accident. (That's my story, and I'm sticking to it.)
The guitarists are excessive. The rest of it, bonkers, probably in a good way.
Dave sold me his Vintage fretless. Nice guy, nice chat, nice bass. Despite my shoddy navigation, it was time well spent. I'd be very happy to trade with him again.
Cheers Dave