I know what it means but does anyone know the derivation?

we had some discussion about jonesin' back at the beginning of the summer...

see if this thread answers your questions.. if not, well, keep plugging away! we might be of help, and then again..
http://wordsmith.org/board/showflat.pl?Cat=&Board=words&Number=30179

before checking it out, you might want to edit your profile, and set to view to 99 posts at a time, otherwise, you might find that the link to page 2 or 3... of the thread doesn't work.