Missing tick box

Hi,

I have an issue in relation to this module. Simply put, I am unable to to tick the box which says "Checking this box will hide this complete field group".

As the screenshot shows, there is no box to be ticked. I changed theme, ran an update, manual cron and cleared caches but to no avail.

I have also encountered this problem with another module (pay-per- node).

My drupal install is 6.16 with the latest dev and 2.0 modules installed.

I used firefox. Did a test on explorer and the theme was all messed up.

I would appreciate if any of you would give me some kind of advice about where to look for an answer if any.

Thanks for everything,
T