CSS'ing TinyMCE on a Diazo'ed Plone site

I had thought that TinyMCE was supposed to remain untouched by the Diazo theme, however some CSS from somewhere is leaking in and making certain functions harder to use. One such example is below, the line height on all the rows has become super short, making each row hard to select.

In Firebug, I can fix this by adding a min-height value here, a value set in dialog.css:

.radioscrolllist .list {min-height: 2em;}

However, I cannot find where to actually set this and have it stick. I've tried putting it in the Diazo theme style.css, in ploneCustom.css, and customizing both portal_skins/tinymce/themes/advanced/skins/plone/dialog.css and portal_skins/tinymce/plugins/plonebrowser/css/plonebrowser.css — none of these seem to do the trick though.

Any ideas on how/where to make this fix? The problem only shows up on the Diazo version of the site, not from the unthemed version. It looks like the only CSS files that load on the TinyMCE iframe are:

• dialog.css
• plonebrowser.css
• columns.css

I just faced the same issue last week. My workaround was adding this in my theme's CSS (the tinymce dialogs are not part of the iframe that contains the content being edited; they are in the main frame):

#internallinkcontainer.radioscrolllist { line-height: auto !important; }
#internallinkcontainer .list.item span, #internallinkcontainer .list.item a { position: static !important; }

(Clearly we should find a less hacky solution, but I haven't had a chance.)