In version 1.4 of SubPageList3, a call of the form

<splist
 parent=
 showparent=yes
 sort=desc
 sortby=title
 liststyle=ordered
 showpath=no
 kidsonly=no
 debug=0
/>

Will cause an error: "showparent=yes has no subpages to list."
"parent=" is treating "showparent=yes" as an argument. I don't believe it previously worked this way. Given that this is the usage example given on the extension's documentation page, I assume this change was unintentional.