I hit 100 several days ago and it stayed that way over the weekend. But, today it is at a 97. I hadn't done anything differently and in fact I had been neglecting hubpages for about a week due to a move.
One thing I did note was that during this time I had 100+ "Fammers" (Fan spam; companies, "professionals" exc.) which began following me. One hubber indicated in the forums that generally your hub score sinks when you become a victim of fammers. But, it was contrary for me. I'm not sure what kind of an impact it had on my score, but, may be worth a shot to get more followers.
I had reported all the fake followers and have seen several banned from hubpages which may be the reason my score dropped down to 97 today.