I can cause xterm to hang reliably with the following command:
perl -mDigest::MD5 -e 'print pack("H*",Digest::MD5::md5("test"))'
A control-middlebutton-"Do Full Reset" is needed to get out of this state.
Konsole doesn't have this problem (but Konsole takes too much screen
real-estate). Anyway, just thought it was worth a mention...
Regards,
Brian.