That could be one reason. Could I ask you to conduct the same test and supply the log, but using another frontend, perhaps Xsane? Also with debugging (SANE_DEBUG_HP5590=50) enabled.
Anyway, the log looks normal for me, except for scanner failed to start scanning operarion for 2nd page. Next step would be to gather Usbsnoop log from Windows machine during the same operation. Do you have Windows installed on some machine where you could do that? -- Ilia Sotnikov
