Inset sites that don't take or go bad?

I'm a mom of a 20 month old little boy who was diagnosed with Type 1, 5 months ago.  He has been on the pump for almost 1 week now and we have already run into a situation where we were told his site was "bad" or it didn't take 2 times in a row now.  We follow the directions word for word and do nothing different than the day we went to have it put on him and had to go through all the steps to get him up and running.  Has anyone else run into issues like this and does anyone have any tips or info as to why this happens.  Upon looking at the site, everything appears normal, nothing out of the ordinary that you can see.  Thanks for the help!!! 

That happened to me before and it was just that I hadn't connected everything quiet tight enough. Just double check that you have the tubing, insulin cartridge and inset connected well is the best advice I have. When this happens is it when you put it in a certain site? Maybe it's in too dense of an area or something (just speculating on that one). If it keeps happening you should call the pump company they are usually very helpful.

So far we have only placed the inset in his upper butt cheek, only because that was the location the rep. from the pump company stated to place it.  It seemed the best area for him for now since he doesn't have much padding anywhere else.   :-)  If it happens again in the future I will definitely check that everything is tight enough though, that we didn't go back and re-check once we found out it was bad.  Thanks for the help!!!