You might try installing the latest HHLIP release. Sometimes a driver
gets broken in one release and fixed in another. This happened recently
with a printer connected to my wifes computer that was running Ubuntu
6.10 and which got fixed with 7.04.

There is an installer to make the update easy. Feisty currently has
hplip version 1.7.3 and the latest release is 2.7.7.

http://hplip.sourceforge.net/install/index.html