What is your operating system?
What are you using to scan?
Can you post a screenshot of that icon?
I have windows 7 64 bit home premium.
I tried to copy the icon, but that will not work. It is the adobe icon, the one with a white background and red triangular drawing with a yellow padlock in the lower left hand corner. I have tried reinstalling adobe but that did not work. However, I figured out that the padlock only shows up when I save it in one of the folders I created. When I installed by printed, the HP program created a folder called "my scans." If I save it to this folder there is no padlock. If I save it to a folder I created for my letters, the padlock is there. Also when I email a padlocked pdf to myself and save it to any folder, there is no padlock.
I'm experiencing similar issues and perhaps my additional information will help lead to a solution.
Using Win7 64bit, symptoms started after I upgraded from Reader 9.4 to v10.1
Padlock shows up on the icon if I save a pdf after making changes (such as highlighting or sticky note) and choose to replace the original file. The locked file will not be visable from other network computers that open the shared folder. I can make the padlock disappear by altering the security permissions for the file, but it still is not visable on the network. My workaround thus far is SaveAs without replacing the original file, either with a different different name or to a different folder.