T.A.
Look at the velcro. Most of the time when the velcro won't stick together anymore its because there is a bunch of "stuff" stuck in it. Like string, lint, fuzzy stuff. I find a large needle or toothpick works well for getting all that stuff out of the velcro. Once its clean it should start sticking together again.
If all else fails, you can buy velcro strips in the sewing/crafts dept at meijers, walmart etc. and you can either glue or sew a new piece of velcro over the old.