When using the repeat_elements function in formslib, the labels accompanying checkboxes are broken. They all refer to the first checkbox element of the repeated set.

Clicking on the checkbox square works, but clicking on the label doesn't.

The reason for this is that all checkboxes get the same "id" attribute, so the labels all refer to the first object with that ID (at least in Firefox).

I have attached a simple fix which solves the problem for me, but I'd like someone well-versed in formslib to review it as it might have some unexpected effects.