Problem when zooming in on a PDF in iBooks
In iBooks, when pinching to zoom in on (enlarge) a section of certain PDFs, entire square or rectangular sections of the document go completely black or white, rendering that portion unreadable until I zoom back out. Sometimes, leaving iBooks and then returning fixes the problem, only to resurface on another page of the document. Sometimes nothing fixes it and I just have to quit iBooks and hope it doesn't resurface on next launch. See the screencaps below.
iPad Air 128GB iOS 7.0.4
iMac, OS X Mountain Lion (10.8.4), 27" 3.4 i7