The Nissan Path

I have a chronic problem with the passenger side front rotor always squealing. So I took it apart and found that the caliper is not releasing well. The pads continue to ride against the rotor when the pedals is released.

Has anyone else had this problem? What do I need to do to remedy this? I did push the pistons out to see if there was any corrosion. None there. I greased them up and pushed them back in.

Often it's one of these problems:
-the pad is not sliding freely within the caliper mount, which could be caused by poorly made aftermarket brake pads or hardware that needs to be cleaned, replaced and/or lubricated with the correct grease specified by Nissan
-the pistons are sticking or dragging in the caliper (meaning the caliper should be replaced)
-the brake hose to that caliper is collapsing internally and not allowing brake fluid to return back to the master cylinder, causing the pistons to stay applied.

Thanks for the input. The pads are aftermarket. They didn't seem to be sliding freely. I tried bending the spring a little bit more hoping that would help to move the pads.

I need to pull it apart again and figure out if the piston is retracting.