Yes, I find that more than half the time I am charged the tax rate for the city in which the post office that serves my address is located; which is about triple the tax rate that actually applies at my address. I put this down to the use of some database somewhere that uses 5-digit ZIP codes instead of 9-digit ones to determine the tax rate.
And the vast majority of the companies that overcharge me in this way simply ignore requests to fix the problem. I vote with my dollars, and tell them that I'm doing so, but none of these companies (i.e., the ones who don't immediately respond and correct the tax on the order) has ever cared enough to fix the problem even after my complaint.
I have to wonder if it's even legal for a company to charge me tax that I shouldn't be charged. What do they do with the money? One assumes they send it to the city in question, but in any case the whole system seems remarkably free of any checks or chances to correct errors.