Fieldset visibility bugs

[Philzen]

i have a fieldset next to an image field, both set to 50% width.

• Setting the visibility to "Always open and cannot be collapsed", the fieldset shows collapsed and cannot be opened at all. Looking at the dev tools the fieldset has the InputfieldStateCollapsed set on it.
• In the default setting "Always open (default)" it will display correctly at first, but when i collapse and open it again (sometimes need to do it twice) one of my field descriptions makes the width of the whole fieldset container go over 50% (which destroys the side-by-side float). Looking at the dev console, a javascript error is thrown on re-opening: Uncaught TypeError: Cannot read property '1' of null in inputfields.min.js?v=13c:1

I am using master (pw 2.6.1), and this problems occur in both recent FF and Chromium. Confirmed with both default theme and reno theme.

[ryancramerdesign]

I can't duplicate this one here. Is there anything special that has to be in the fieldset? I'm testing in 2.6.13, so it's also possible that the issue no longer exists, but I don't recall fixing anything in this regard before. From this side, I'm testing with a Fieldset at 50% containing two text fields, next to a populated Images field at 50%. I tried different visibility statuses with the fieldset (beyond those you mentioned) to see if I could trigger the issue, but no luck.