I have years of experience with burned CDs and DVDs. I've kept a database to track the variables involved like: Disc brand, disc format, burner used, burn speed, and software used. I've followed all of the recommendations for burning discs by using only Verbatim or TY discs, burning at 4x speeds, and using the best burners on the market. Despite all of this, my burned discs will eventually skip on any player over time. So I've come to this conclusion:
Home-made (burned) discs are made differently from professionally made (stamped) discs. As a result, burned discs are less reflective, and require more strength and precision from the player's laser. Over time (usually 2-3 years from my experience), the player's laser loses enough power and/or accuracy to begin skipping when playing burned discs. Stamped discs will still read accurately because they are much easier for the player to read. When I loan burned discs out, I often hear that they skip on other people's players too.
I haven't found much information on this subject, but I do have a lot of experience with this issue, and I think this is what's causing misreads. I'm looking for confirmation of my hypothesis from professionals, but have yet to receive confirmation.