There are many possible reasons:
1. The cable you use is wrong (possible if you use the same one everytime).
2. The jack in the guitar is too loose, can be fixed by pushing a little to the middle the piece of metal in it.
3. There's a problem with the pickup selector. This is what happened to my LP, if it's the case, you may have to change it.

and the worst...

4. Your pickup is screwed up. This is the most expensive thing to fix.

You should take it to repair instead of buying the pod, or take the risk of opening it and finding by yourself (don't do it if you don't know about electronics).