I have experienced pauses and glitches after 30-45 min with my stickered DVD's. The DVD player seems to run rather hot and may be causing the glue to expand. However if I burn my DVD's at 2X rather then 4X I don't seem to have the same problem.
I've really gotten into making elaborate DVD labels and would hate to just write the titles on with a marker. I use RITEK DRD-47-4X-RDSM media but am considering trying the slightly more expensive +R version, that may work better.