Stretching doesn't create imbalances, but it can show them.
Do you know what side you're getting the popping/pulling on.... inferior/superior/anterior/posterior or multiple combinations of the sensations?
I couldn't actually tell too well from your description... well, actually I should be in MOn so you can ask/show me then if you want.
You remember what i told you about stretching the shoulders when you were getting the clicking? Same things applies here.
Could be tight capsule, ligaments, tight muscles, etc. It's pretty hard to tell what's going on without some more in depth testing and stuff like that