Wallpaper and Wallcoverings - Border: edges curl, won't stick - help?

We have NO experience and little direction: We put up a new prepasted vinyl border mid-wall in a small room, color pain on the bottom half, white paint on the upper half, border in the middle. The walls are farily rough and textured, almost like outside walls. If you run your hand hard over the walls, you'll get slightly scraped up. Couldn't find anything saying to level this out, and if so, it would be hard for a border in that mid-wall position. We used something called "prepaste" activator and brushed it on. We let it sit for 5 minutes as directed and it dried up, wouldn't stick at all. So we tried brushing it on and skipping the 5 minute wait - it stuck to the walls - barely. The edges won't stay down and at the ends, there are places it is completely falling off. It is most discouraging. We have one roll remaining, but it's not enough to redo the whole room. Any suggestions or help? p.s. with the wallpaper on, the texture of the pebbly wall is in the paper now, if that gives you an idea of the texture of the wall. My only thought is thin chair railing nailed to the top and bottom to hold the edges down but my husband isn't thrilled with that idea. Thanks...

Does`nt sound like the best surface conditions to stick a border to!!
Try using vinyl border adhesive..and a rubber wheeled seam roller for the edges. If the edges start to come away after a few mins then roll over again and they should stick...

Attach a thin piece of wood ( 1x or less ) as wide as the border, to the wall. Caulk along the top and underside of the wood where it meets the wall. Put the border on the piece of wood. You may want to sand the edges a little to cut down on splinterage.