I would expect the front sight to stay in place as it was factory installed but it and the rail are both coming loose while at the range after 50 rounds or so.  

Whats the best way to prevent this?  

I have used blue lock tight before and it stripped the finish off a 10/22

Any ideas?

I had the same problem with my 22/45 lite. Just take some rubbing alcohol (or similar) and clean the screws and holes making sure to get any oils or residue off. Then use some blue locktite ( I think I used blue #243) on the screws and re-assemble. Wipe off any extra locktite when your done. I've never had blue locktite affect the finish of a gun before? Just wipe off the extra before it dries and you should be good.

Blue Loctite won't hurt the anodized aluminum.  It will eat off the paint on some of the newer 10/22s for some reason, not seen it on any other guns before, but the anodized finish will definitely be ok.

Same thing I did- Mine almost fell off after a few rounds on its first outing.  Luckily I noticed it as I was standing in a field.  It seems to be a common problem with these guns.  

Me too with the front sight getting loose.  Just ordered a picatinny rail for it, so I'll tighten them all down at the same time.

I just bought a 22/45 lite, same issue with the front sight.  I cleaned the screw hole and the screw with some degreaser and used blue permatex thread locker from autozone. I only shot 100-200 rounds since, but the front sight hasn't loosened.