Not sure why the .3 update would have stopped you from duplexing. Hasn't impacted duplex printing to my printers.
To confirm, you are able to select the duplex setting via the Layout tab or via a HP finisher menu as you have done previously but the printer does not print on the second side.
If you haven't done so already, try removing the printer from Print & Scan and adding it again. I would also check the driver settings in Print & Scan > Options & Supplies > Driver to ensure that you have the Duplex setting enabled - assuming that such a setting exists.
If the above does not help then you could try a reset of the printing system. This will remove all printers and scanners from Print & Scan, but not the supporting drivers, so you will only have to add them to Print & Scan again.