When using the Safari browser included in Mac OS X, the execution of a spell check operation will mingle certain characters in the source of the page, causing all lists to be broken upon the next "Preview" or "Save" operation.
We experience this behavior with DokuWiki running on both a Linux server and a Mac OS X server. I did a capture of the traffic between the Safari and the server (included as file "safari" in the attachment). For reference, I also captured traffic between Camino (=a browser that does not exhibit this behavior) and the same server.
Jugding from the diff between these two captures, things go different when the browser calls the "resume" function of the spellchecker to convert the text from HTML back to plain text. Camino's HTML starts each item line as such: (in URL-encoded form)
Whereas Safari has:
So Camino has " " where Safari uses "\xC2\xA0" (the latter is the UTF8 encoded form of U+00A0 or NO-BREAK SPACE).
$text = preg_replace('/\xC2\xA0/',' ',$text);
This solves the problem for me.