I've tried to search for these and can't find the answers. Help please. 1. Tried opening a PDF file (2mb) on my gmail application. Tried to open "PDF Viewer" and it said "file can not be viewed. I know the PDF is a good file because it opened just fine on my computer. I have tried to open other PDF's and they work just fine. Any suggestions? 2. Tried to open a video as a wmv file on my gmail application. Loaded fine with sound only, no video. Any Suggestions? 3. Is there a screen lock feature where you can put your phone in your pocket while on your bluetooth headset?