I had two small bubbles appear in my just finished kitchen paint job. They are 1/2 x 1 inch and 1 x 1 1/2 inches each and close to each other. The rest of the room is fine. I popped and peeled them and the previous paint layers all came up as one. The substrate left is bare drywall and some mud or spackle nearby. It looks like no primer was ever used or it just came up with the other paint. What caused my latex to make these areas bubble? My wife recalls the old owner had wall paper before and that we had some guys paint the kitchen about 9 years ago. Maybe they did bad prep? What about repair? I was thinking of letting the new paint cure/dry for at least a day and then sand the area feathering it out. Then oil-base primer (to be safe to stick to whatever is there vs latex primer), retexture, prime the texture and then paint to match the rest of the wall. Thoughts?