I tried using a "fake oai server" for the harvester test in xmlui that was internal to our university and not only did it output something other than "OAI server could not be reached" (was "OAI did not respond to ListMetadataFormats query (:null ; :null): null"), but it didn't hang for a long time either. So I'm reasonably sure the problem is that it's not using our campus web proxy to contact the bepress oai server. Checked both the tomcat and dspace logs, but nothing in there related to this.
If someone knows which proxy settings the xmlui harvest test uses (tomcat, local.cfg or ???), I'd really appreciate it.