Hi liviococcia,
Would you try the following steps to see if it works?
1. Uninstall the current HP Smart Web Printing installed
2. Launch Lunascape. Go to Lunascape Settings>General Settings
3. Change your default engine to Gecko. Restart Lunascape.
4. Download the HP Smart Web Printing (
http://www.hp.com/global/us/en/consumer/digital_photography/free/software/smart-web-printing.html?jumpid=ex_r602_go/swp)
5. Go to View>Gecko Tool Bar
6. Gecko Tool Bar will shown. Click the Gecko Icon drop-down menu.
7. Go to Sidebar>HP Smart Printing
If the above won't work well, try "Extended Mode (Gecko)"