Yep, those are the types of things that change it. "too much activity" or any activity really disturbs the 'fine balance' that is your credit score. Shhhhh, you'll wake him up.
Smurfy, answer! Seriously, why is your score like that? They should provide an explanation if you got it from one of the 3 agencies.
Don't cancel any cards, don't do anything "harsh". lol Just pay everything off like you've been doing and make sure you don't have a BS collection or error on your report.