Jill, ultimately you will want to upgrade to the V2 sprockets and masts. In the meantime, you can certainly epoxy the masts and screws in. I've had very good luck with Loctite Marine Epoxy for the masts and Loctite (red) permanent thread locker for the set screw. The marine epoxy may also be sufficient for the set screw though.
When you put the screw in, make sure it is fully seated in the sprocket. Here are a couple of views to help. If you have any problems, don't hesitate to break out the metal file and get rid of that center ridge if necessary.

The above picture shows the screw properly seated.


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Since you can't look inside like this, the depth of your set screw will tell you if you're fully seated.
When done, you shouldn't have any further problems.
