If I turn off the "Documents Bar", close Zeus, and then re-open it, the code fold margin no longer displays the expand/collapse icons. (Code correctly folds if you click where the icon should be.) Turning the bar on then off again fixes the issue.
Not a big deal, but thought I'd report it.
Code Folding expand/collapse icons and the Documents Bar
Thanks for reporting this issue 
The new beta version from the link below should fix this issue:
http://www.zeusedit.com/z300/ze397r-beta.zip
Cheers Jussi

The new beta version from the link below should fix this issue:
http://www.zeusedit.com/z300/ze397r-beta.zip
Cheers Jussi