I've been trying to open some pdf documents and have downloaded version 9 of the pdf reader. However, every time I open a pdf, after about 5 seconds, a message flashes up saying that I either have to quit or purchase the full version. I did have a 30 day free trial of the full version last year, but didn't purchase it. Could this be the reason? Can Adobe stop me using the free Reader because of that? Help would be much appreciated!