RefWorks connection refused

Here at Brooklyn College we are experiencing a  problem with RefWorks tool. It work fine when you access it on campus and produces an error (“Connection refused by, please try again later”) when connecting off campus through ez-proxy. Our ez-proxy configuration is an exact copy of what is suggested by OCLC. We noticed that this problem occurred as soon as  RefWorks changed IP addresses of  their servers. Does anyone experience the same issue?