It look likes that you receive not an adaquate name for your computer.

Which network setting do you have?
It's necessary that you have a valid network name (host name) for you computer and not the generic one.

Regards
Martin

Thy main problem is, that in some situation JXTA can not resolve the IP address correct. This throw an exception in JXTA and open this JXTA configuration dialog. We are in touch with the JXTA team how we can suppress this dialog and can open our own screen.

In the next release it should be solved.

Director of Engeneering
Martin G. Heinrich