I'm assuming you tried all the options (restart). Does it just keep asking for paper after you've loaded a sheet in it? I'm not a tech person and don't know exactly what is happening based on your post.
The problem might in the printer, not the HP computer software/driver if the printer isn't recognizing ANY paper. The paper sensor could be damaged or have something blocking it. If your printer recognizes rolls than this isn't your problem.
There also is a paper size limit, the page has to be 8.5" wide. I don't go any smaller than 8.5 x 11.
Someone has posted here about an HP tech person to call if you don't get the support you need. I'll see if I can find that post.
Some users have created this wiki page which might help.
http://z3100users.wikispaces.com/Good luck,
Doug