I've encountered the same problem and as I recall it's a glitch in the page set up. When you are in the LR print module, click on the page setup button and make sure that the paper size and choice of printing (landscape/portrait) are what you want. Double check this when you hit the print button to make sure that there is no conflict. I'm pretty sure that's how I resolved this problem. Funny thing is once I've created a print template, the problem never occurs. Anyway, to the best of my recollection, that is how I solve this.