Yea I have that trouble as well, and I have thought about it and have come up with this yet to be fully tested solution.
Cut an inch or so of antenna tube and CA glue it in to its hole in the reciever box. About an inch sticking out should be fine I reackon.
Now push about 2 inches of fuel tubing over that and push the remaining antenna tube into the inch of fuel tubing thats sticking up so you have a replaceable antenna tube that shouldnt come out in a hurry.
It may be a bit floppy with the body off, so if you run that way it may be dodgy, but with the body on it should be sweet.
Also maybe try different lengths of tubing and see what works best.