The only time I recall being really annoyed was when DC Comics and Pocket Books, who had been happily cross-pollinating little tidbits for some time, put out conflicting "first mission" stories simultaneously for the 20th anniversary. "All Those Years Ago..." (TOS Annual #1) and "Enterprise: The First Adventure" (giant novel #1) clashed in numerous ways, and both would have been so much more fun had they gelled as regards which crew had come from Pike's command and which members were the new arrivals.
From then on, I let those types of quibbles challenge me. Probably I was inspired by the "Star Trek Mysteries... Solved!" articles in the "Best of Trek" books.
Best reverse death: Garrovick, who'd been killed off in "Home is the Hunter", a post-TMP story, and was the cause of Kirk's depression in that book, was miraculously still alive in the post-ST V novel, "In the Name of Honor". A cause for celebration.
So, do errors/contradictions bother me? Only when it concerns some aspect of ST that I'm a stickler for. For example, I never
care if the stardate or warp factor is wrong; I rarely even notice if they are!