i personally don't trust/like velcro's glue and usually hand/machine sew on velcro. i've tried "wet" glues and that soaks into the front and still doesn't hold 'cause of the pulling action to separate the velcro.
i've never tried this . . . but there's some heat & bond ultra http://www.joann.com/joann/catalog/p...RODID=prd49052
you may have trouble w/your sewing machine needle gunking up going thru the glue if you do decide to sew . . . so i'd suggest getting velcro w/out glue . . . to be 100% sure it won't come off.