Hello there Rui,
Welcome to the Forums!:)
Sorry to hear about the problems you are having with scanning from your PSC 2210. I have checked for a firmware update and there is not one available for this unit as of current.
I would like to suggest trying this troubleshooting document and also to ensure you have the printer plugged in directly to the wall socket, avoid ALL power bars, surge protectors, battery backups, and extension cords. A direct connection may help out quite a bit.
If the troubleshooting does not help resolve your issue, I would then suggest calling HP's Technical Support to see about further options for you. If you are calling within North America, the number is 1-800-474-6836 and for all
other regions, click here: http://www8.hp.com/us/en/contact-hp/ww-contact-us.html
All the best! :)