I have had my VP112 for several years now and the same problem keeps showing it's ugly face. Why do the bag fill with air when I and trying to seal them. Here is what I am doing. I put the meat in the bag making sure for a clean seal area on the bag. Put the bag in the machine and lock it down with the bag clip and hit the start button. As I look into the chamber I can see the bag filling up with Air as the machine vacuums down. This makes the bag swell and causes the seal area to buckle and not be flat anymore. This often causes the seal to fail making me to have to retry. I have the vac set to 40 and the seal set to 7 I have played with these and still it happens. What am I doing wrong.