I haven't seen this myself, but this is a definite possibility. And although one should make sure the installation is complete, that is no excuse for barfing out like this:
2013-04-24 16:05:43,822 connection lost: invalid packet header byte: '0x63', not an xpra client? \ read buffer=0x63616e6e6f74206c6f6164207832363420636f6465633a2063616e6e6...
So we should make sure we don't print warnings to stdout, and maybe also capture the ssh process's stderr and show *that*.
r3147 should prevent the error above (which was due to a missing picture codec)
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/326