Burning discs (DVDs and CDs) at high speeds reduces the contrast of the burned area compared to burning at low speeds.
Cheap and/or sub-standard lasers in disc readers have troubles reading this. It sounds like the Dell has this problem. I know way back in the day (when CD burners will still $1000 and discs where $10 each) burning some CDs at "high-speed" - 4X (that was insane speed back then) would render them unreadable in many standalone CD players with older tchnology inside them. We had to stick to 2X, or the contrast just wasn't good enough for the old players.
Anyways... for compatability reasons I generally burn stuff for others at much lower speeds, and stuff for myself at the max speed my media can take. It solves a lot of these sorts of problems.