I was having the same issue with telnet.  I added /ipv4 to the end of the end of the command and it worked fine. router>tel cisco.comTrying 0d.0b0d.0b0d.0b0d.0b0d.0b0d ...% Connection abortedrouter>tel cisco.com /ipv4Trying cisco.com (72.163.4.185).....