We're fixing some stuff in the sequel. It is an interesting thing to go through with someone else. For One Too many Blows To The Head we really didn't alter any plot points, locations or anything you'd call significant. For this one we've made some course corrections that ripple down the line and require minor fixes in several chapters. Some of it could be described as major but the integrity of the plot and the character's motivations remain the same so I don't consider it very major. Nor would I call anything a 'problem'.
Revising on my own is relatively drama-free but doing it with a partner presents a whole different set of challenges. Challenges, I am happy to report, Jennifer and I have once again met and handled easily and with no quarrel. The hardest part is keeping the consistency between us. Little things have come up like how badly someone's injury was from one chapter to another (and we've got lots of injuries in this one) to simple stuff like what color car someone is driving to minor character names.
This is the real work in writing. It still beats a real job.