Portage has 1.4 version while the 2.3 was released 2004/05/09. The major difference is it includes a pst-xkey package now, which is used by pstricks-add package (this package is not in portage at all, although it should be IMHO) Reproducible: Always Steps to Reproduce:
Created attachment 52800 [details] ebuild for xkeyval-2.3
Thanks, added to CVS.