What is you TERM set to in HP-UX? I have used putty to run SAM without a problem. Everything looks great. MY TERM is set to vt220 Also in your PuTTY configuration when you start a new session, go to "Connection" and in the "Terminal Type String" field, put in your Term type, vt220.
Then after you log into the HP-UX machine, do an 'echo $TERM' and see what your terminal is set to. If it's not vt220, set it to that 'export TERM=vt220' and then see what happens.