classes and id(s) attributes

hi all,

with 1.2 update all css classes disapears from field_group dom node, and were replaced by an id.
i can understand the main idea, but what if you display many nodes on one page ? results is you have multiple identical ids in the same html page, too bad !
you can see my point with this site i'm working on, here with field_group 1.1 : http://www.materio.com

what do you think about it ?