Did you ever get this to work?
I got my Mustek 600 III ep working after a bunch of messing around, and during the process, I received a lot of the same message, and it was due to incorrectly specifying the scanner's device name when trying to access it. Instead of telling me 'device not found' or something useful like that, it told me 'Device Busy'.
By using the 'scanimage -L' command as root, and a few other things, I was finally able to specify the correct device. Now, the fastest way for me to scan a basic image is like:
Code:
scanimage > /path/to/saved/image/filename
and if you run this command as root at the command line, and it works, then all is likely set up just fine.
One thing I DID have to do, in order to use for example GIMP to scan images, was run GIMP as root, because by default the scanner device/device node is owned by root. Rather than change the permissions, I just made a desktop link like 'kdesu gimp-command' and problem solved. You may choose togo the permissions route.
And btw, GIMP has an awesome scanner interface which works 110% great with my scanner!
For more info on my exact course of action, search LQ for posts by me, containing the words 'mustek 600 scanner' and I'm sure you'll find it easily.
SV