Sales Tax

I have used a price sheet in shoot proof for over a year now. I haven't edited it at all as it's one of my go to sheets. Where I live I have to charge sales tax on digitals. All of a sudden in the last couple months it quit charging sales tax! They are of course blaming me, but I am 100% certain I did not edit this, in fact they had to teach me how to go in and change it back as I had forgotten how to even go in to edit this. Anyone else experience this? I wouldn't post this unless I was certain, so I'm just passing it on you may want to check often to make sure you're collecting the correct amounts!