In the bison product options fieldtype I seem to be limited to five options per option group, after that, it breaks and the selector on the web page disappears. Is this normal behaviour?

I am working on a store for a jewellery line, there are many sizes from 5 to 11 with half sizes, after size 7 the selector on the site disappears. Screen Shot 2014-11-26 at 10.30.35 PM.png