Drupal Accordion has limited items

Hello everyone, i have this issue, i have put some accordions inside tabs and it seems that when i reach to the 9th accordion item it opens, but if i go further it won't, if we take the numbers from 0-9 the items open, then if you click on the 10th item it opens the first one, if you click the 11 item it opens the 2 one in the accordion. Can you pleaase suggest me what to do...here have a look at this :

http://plus-demo.info/test/en/individuals-support-zona-plus-network