You need to slide the clamp down so the short post is straight up and down. It should snap in alot easier then. This keeps the top from riding on the fiberglass.
No I didn't get the fill in but I have an issue with my Bimini and thought I would see if anyone else has it as well.
I can't get my short posts from my Bimini to fit into the socket - seems to me something isn't mounted right. Also when trying to get the short post in, there is a rivet on the front pole just above the cover snap that scratches the gel.
here's the pic:

It looks like it should fit but it just won't lock in - long posts are no problem. My dealer is a waste of time - I've called him three times and emailed but still no response. Sure wish there was a FW dealer closer to me.... (I went 5 hours for mine).
Anyone got pictures like this of theirs which works?