I have found a number of ebooks that I have purchased have some glitches in the encoding. Most often I notice that the pages are mapped incorrectly. For instance, in one case I advance to the next page from 121 and it returns me to 117. In another instance, I advance from 91 and it takes me to page 192. The pages all exist and going in the opposite direction does not seem to have the problem, though I have found a few cases where it did have quirks going backwards as well.
Is there a way to correct this locally without stripping the DRM, finding the incorrect encoding, and fixing it manually? Is there an established channel to go through for reporting these glitches?