Scanning to a networked scanner through Preview in Lion

For yonks I've happily used the scanner function in our HP Deskjet F2280 through Preview, by 'Import from Networked Devices' as the Deskjet is connected to my wife's iMac.

Since I've upgraded my MBP to Lion, this is no longer possible - the option is greyed out. I can still print with no problems.

Any idea wassup? I've installed the latest drivers and etc. Do you think I need to also upgrade the iMac to Lion? - it's Snow Leopard atm. That'll cause a bit of a stink as she still uses some legacy software that won't run in Lion.

Thanks