I find this problem is caused by using unusual sized windows. ie. not 80x24. If you spawn off a dtterm or hpterm at 80x24 and try it again it should get around the problem.
From a dtterm you can go to the menu bar at the top of the window and do a soft reset which will fix the lockup on one line.
For a more permanent solution you need to fix your .profile, there are some terminal test commands in there which cause the lockup on non regular sized windows. Try removing the .profile and that should work. Then you can create a new .profile and only add in what you need.
Im from Palmerston North, New Zealand, but somehow ended up in London...