I purchased and loaded expert pdf6.0

I purchased and loaded expert pdf6.0 with very unfortunate results. Immediately after loading it I experienced difficulties with microsoft word 2007 (home & student version). Word kept crashing when I tried to close the document I was working on. It took me some time to realise that it was your program that was the source of the problem. In the end I had to offload all my files and use the PCs recovery disk before reloading all my programs. Everything worked fine until I re-loaded your program when the same problem occurred again. I uninstalled it and the problem has disappeared. Do you have a solution? I previously purchased pdf5.0 from you and that program worked well although it was far from convenient to use.