You said your crib tent did not fit, right?
I just noticed DH had to add some very strong velcro to ours. I know the instructions say not to, but he did and we have never had any problems. It's been a year. On each piece of velcro he added a thick piece of black velcro.
Can you do something like this to yours? Our crib has a high back also.
Re: *melmax*
Let's see if this pictures works. DH just got the really thick velcro from Home Depot or something. It comes in a roll and you can cut how much you need. You would just need to make sure you keep it tight. KWIM? I will run take a pic of it, but here is one without the tent on it.
Here it is with the tent.
HTH! If you need me to ask DH anything I can.