I suspect that Tk doesn't like being run in more than one thread. POE by itself is entirely Perl, so it doesn't do funny things with memory pools. One work-around is to avoid Tk; does Gtk work instead? If so, then Tk is probably the culprit.
cmv is having the same problem, which you can see at this node. It might be helpful for you to consolidate nodes and notes. He was also nice enough to open an this rt.cpan.org ticket. If you are logged into rt.cpan.org, you may be able to add yourself as a Cc on that ticket. Then you should receive automatic progress updates when there's news.