You may be right. I've only had experience with weird issues on unreserved trains (Keystone and Surfliner). On the Keystone, I'm usually using tickets for vastly different dates than I've purchased them for, which would understandably make it hard for them to look up my information in an area of bad coverage.

No idea what happened with the Surfliner trip yesterday--I was traveling on the exact train I had chosen during the booking process. (In fact, I showed up at the Santa Fe depot early enough to take the next earlier train, but when I saw it was using the single-level Horizon/Amfleet equipment, I went across the street to Starbucks and worked for an hour and a half until my originally-booked train, which (fortunately) had the bi-level Surfliner cars in its consist.

As an aside, I picked a rear-facing seat in one of the Surfliner cars, figuring that the lone Superliner car in the consist would not be outfitted with wifi and power. I walked through the Superliner car later and was shocked to discover that not only did it have a strong wifi signal, it also had two power outlets per seat, compared to the single outlet per seat in the Surfliner cars! Lesson learned for next time.