1 answer
Hm. What browser are you using?
There may be an unadvertised limit of 15... I don't have access to an Org. that has it installed so I can't do any testing at the moment.
It's free and technically support isn't offered, but you may want to reach out to Salesforce directly or if you're a twitter user, tweet your question with the hashtag #.askforce.
Best,
David