Comment 2 for bug 525789

Here's my output:

$ sudo hp-scan
warning: hp-scan should not be run as root/superuser.

HP Linux Imaging and Printing System (ver. 3.10.2)
Scan Utility ver. 2.2

Copyright (c) 2001-9 Hewlett-Packard Development Company, LP
This software comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to distribute it
under certain conditions. See COPYING file for more details.

Using device: hpaio:/par/HP_LaserJet_1100?device=/dev/parport0

warning: No destinations specified. Adding 'file' destination by default.
warning: File destination enabled with no output file specified.
Setting output format to JPEG for color/lineart mode.
warning: Defaulting to '/home/sam/hpscan001.jpg'.
Using device hpaio:/par/HP_LaserJet_1100?device=/dev/parport0
Opening connection to device...

[[[LONG DELAY HERE - pressing scan button does nothing]]]

Resolution: 300dpi
Mode: color
Compression: JPEG
Scan area (mm):
  Top left (x,y): (0.000000mm, 0.000000mm)
  Bottom right (x,y): (228.599991mm, 381.000000mm)
  Width: 228.599991mm
  Height: 381.000000mm
Destination(s): file
Output file: /home/sam/hpscan001.jpg
error: Unable to set option mode to value color

Warming up...

Scanning...
Expecting to read 11.0 MB from scanner.

[[[TAKES AGES, SOMETIMES WORKS]]]

Reading data: [******************************************] 100% 11.0 MB
Read 11.0 MB from scanner.
Closing device.

[[[CLOSING TAKES AGES TOO]]]

Outputting to destination 'file':
Saving to file /home/sam/hpscan001.jpg

Done.

The actual scan was good.

If I specify -mgray, I don't get the complaint about colour but it still has the big delay on opening.
-mlineart

Sometimes I get:

Warming up...

Scanning...
error: SANE: Error during device I/O (code=9)
Closing device.

or

Destination(s): file
Output file: /home/sam/hpscan002.jpg
error: Unable to set option mode to value lineart

Warming up...

Scanning...
error: SANE: Device busy (code=3)
Closing device.

or

warning: Defaulting to '/home/sam/hpscan002.jpg'.
Using device hpaio:/par/HP_LaserJet_1100?device=/dev/parport0
Opening connection to device...
error: SANE: Error during device I/O (code=9)

turning off and on again makes it work again.

hp-scan "can work" but is very unreliable.

xsane hp-scan is harder to see; I think it's worth debugging hp-scan first.