Two-sided printing for HP CP2025

[Farid Najm]

I have an HP Color LaserJet CP2025 with the Duplex unit installed and no Tray 3. It has Letter sized paper in the (only) tray, Tray 2. It is connected by USB to a Mac Pro (2x2.8GHz Quad-Core Intel Xeon) running Mac OS X (10.5.8). The printer was "set up" by simply connecting it to the Mac, as opposed to setting it up via the CUPS system (which I gather is another way of doing that). I can print just fine from Mac applications, in either one-sided or two-sided formats, no trouble at all.

When I look up this printer using the CUPS system, I see that the options are correctly set so that, under General, the page size is LETTER, the paper source is Tray 2, and the 2-sided printing mode is Long-Edge Binding.

However, when I print from the Terminal window, I cannot print in two-sided format, even if I say "lpr -o sides=two-sided-long-edge <filename>". It will print, but comes out single-sided. Help!