From the tite-bond web site...
Can surfaces that have been painted or stained be bonded using Titebond Wood Glues?
Most of our glues are designed to bond bare wood. Painting or staining a wood blocks the pores, keeping the glue from penetrating into the wood. The Titebond Polyurethane Glue may work for gluing together painted or stained surfaces, but it is necessary to remember that the overall bond will only be as strong as the bond between the paint and the wood. We recommend that all substrates be clean of any type of paint, stain, or sealer.