This is because the original version is no longer in development, as stated on
the website at http://code.google.com/p/partiwm/wiki/xpra:
"This project is in deep hibernation; I haven't had time to devote for several
years now. If you are looking for xpra, you may prefer Antoine Martin's fork,
which receives more support. It is available at: http://xpra.org/"
So I guess its safe to switch over to that fork.
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