So, along the right side of an 11x14 print I find this ...

neatly printed.
I'd like to think it wasn't doing maintenance while printing but I did print that at about the same time it does its daily noise fest. Or perhaps there was a driver issue. Or maybe the printer just went nuts. Or maybe it knew I was using epson paper.
Just thought that was interesting. I think I'll be emailing HP tomorrow.
Oh, 11x14 Epson glossy paper (had a box laying around) printed as HP Advanced Photo Glossy (prints very nice minus the black boxes) through CS2 with the Photosmart print tool.