Purchased Nitro pdf about a year ago at Office Depot. Have used it past year no problem. Suddenly, it has "converted" to a trial version. Of course, I didnt save the box from a year ago. Unless I pay them ANOTHER $80, and am able to download a "serial number" (never a requirement of the off the shelf product I bought a year ago), it prints a "Trial Version" yellow box at the bottom of my documents. And, of course, they have NO form of online or call-in product support, you can only fill out an online form and have no way of knowing if it will be received or they will respond. BEWARE of Nitro pdf!!! Dirty business! read full review »