Black Hole
May contain traces of nut
Yes, this is definitely a DOS / UNIX conflict. I don't know PuttyTel but you need to look for a setting (in PuttyTel) which changes the output resulting from pressing Return from CR+LF to just CR (or perhaps LF - I can't remember which).
Update: a quick Google suggests PuttyTel is not good in this respect - you need a different Telnet client. The Windows client isn't great, but at least I can make it work properly by starting with the command "unset crlf". It's easy to tell: when you get the "humax#" prompt, press Return. If you get two prompts in response instead of just one, the EOL (end of line) setting is in DOS mode rather than UNIX mode. This sometimes doesn't matter too much (when issuing single-line system shell commands), but as you have discovered (when engaging in an options dialogue) the extra EOL can cause havoc.
Update: a quick Google suggests PuttyTel is not good in this respect - you need a different Telnet client. The Windows client isn't great, but at least I can make it work properly by starting with the command "unset crlf". It's easy to tell: when you get the "humax#" prompt, press Return. If you get two prompts in response instead of just one, the EOL (end of line) setting is in DOS mode rather than UNIX mode. This sometimes doesn't matter too much (when issuing single-line system shell commands), but as you have discovered (when engaging in an options dialogue) the extra EOL can cause havoc.