OK,  I'm trying out 1.4.2 and 1.8rc3.

I have my code shared in such a way that I can run the exact same markup through jquery1.3.2 and UI 1.7.2,  or I can run it though 1.4.2 and UI 1.8rc3.  The only other difference is the theme.  I'm using a downloaded gallery theme for the UI 1.8rc3 (checking the 1.8rc3 radio prior),  a custom theme for the UI 1.7.2. 

My Accordion is different under UI 1.8,  there is a line break after the icon in the header,  and there isn't a line break on UI 1.7.2.

I vaguely remember the very first time I played with accordion that I saw this.  It's possible I may have hacked up my 1.7.2 custom theme,  but I don't think I did.

In Firebug,  the HTML looks identical in both cases.

Anybody have a clue?