Blue Mountain Wallcoverings NS026444 Go Diego Go Self-Stick Wall Border

I ordered 2 sets of these (along-with other wall coverings - Cars, Dora, Princesses and others) and these are the only ones that don't want to stay up on the wall... They came down (the first time) in less than 15 minutes. The weird thing is that, they stick to each other much better than the wall! This sure is a waste of time and money. I gave it 2 stars since the pattern is really appealing.

This is such a great design but what's up with it not sticking? I just put it up (very easy to put up) and now it's coming loose. I reattached it to the wall but expect it to come back down soon so I'm thinking how to keep this beautiful peace of art up on my child's wall.