My neck pup keeps sort of sinking after a few weeks on the side of the low E. Is this a major problem? I don't mind readjusting it every few weeks. Also, its kinda wiggles from side to side when I prod the sides of the pup. I mean the bits that contain the pole pieces. Is the pup defective?
Sounds like the springs are worn out or maybe even missing. The two screws you adjust the pickup with have springs around them to keep the pickup steady. They are easy to replace.