Unable to scan from HP C3180 on Ubuntu 9.04

I've had a HP C3180 colour inkjet printer for more than 3 years. However I don't really use it much for printing from the computer. As a multifunction printer, its handy to make quick photocopies (scan and print without being attached to the computer). I also use the scanner to make electronic copies of important documents. Oh, and the built-in multi-card reader (SD, MMC, CF) has been handy on occasions. However I noticed some time ago that an upgrade of Ubuntu (maybe to 9.04 - I can't remember) resulted in the scanning functionality being unaccessible. Running scanimage -L as a normal user did not detect the scanner (however running as sudo did), and using xsane resulted in an error along the lines of Failed to start scanner error during device I/O. After a bit of searching I guessed an upgrade of the HP printing software could help. The version of hplip that comes with Ubuntu 9.04 is 3.9.2. An upgrade to the latest version (3.9.12 in Feb 2010) fixed my scanning problems. Simply download the binary from the HP Linux Imaging and Printing site, open a terminal and install:
cd Desktop
sh hplip-3.9.12.run
A number of questions are asked, the necessary Ubuntu packages installed, and the hplip software compiled and installed. To test:
scanimage -L
(run as normal user) recognizes the scanner/printer with output like
device `hpaio:/usb/Photosmart_C3100_series?serial=MY69CC540R04KV' is a Hewlett-Packard Photosmart_C3100_series all-in-one
Now when I turn my printer/scanner on, xsane starts automatically, allowing me to scan.