Fieldsets are missing the form-wrapper class, from form.inc:

  // The .form-wrapper class is required for #states to treat fieldsets like containers.

I was having some trouble with visibility state not applying correctly for some items (seemed to work sometimes, other times display: none; was applied to each form item rather than the fieldset itself), adding this to preprocess_fieldset appears to solved the issue:

  $vars['attributes']['class'][] = 'form-wrapper';

Just for clarify my fieldsets are in vertical tabs.

Comments

timcosgrove’s picture

timcosgrove commented

This is a duplicate of http://drupal.org/node/1105086 .

coffeymachine’s picture

coffeymachine commented
Status: Active » Closed (duplicate)

I'm going to close this as a duplicate of the issue mentioned above #1105086