CCK collapsible fieldset legend disappears when collapsed

Description: Click to collapse a collapsible fieldset in node/add form. Result: legend disappears (entire fieldset is now inaccessible.)

Setup: I'm using Mothership as a base theme for ninesixty, and in turn using ninesixty as a base theme for my custom subtheme. I have verified that this issue still exists if I simply use Mothership as my theme.

I am not sure how Mothership is interacting with the system module in this case, but the css responsible for this comes from system.css (line 310: html.js fieldset.collapsed * {display: none;}). In my browser tools, I can fix this by assigning a style of display:inline to the span that contains the label. But here is the interesting part: I cannot get the form to obey my theme css file! Other parts of the page read it just fine - but the form ignores it.

I have figured out a hack to temporarily fix the issue: I opened up Mothership's template.form.php file and modified line 87, adding 'style="display:inline"' to the span tag.

But I do want to style this form with my theme's css. If you don't have a Mothership fix for this, is there a snippet I can add to my subtheme's template.php file that will let me do this?

I dig Mothership, but if I can't style my node/add forms, I will need to disable it!

thanks,
Dale