FWIW I connected to my empeg (beta 11) using hyperterminal last night, with no problems. This was the first time I had used a serial connection since 1.03, and the .ht file was unchanged.
I would check the following:
Is anything using the serial port?. Do you have a palm or handspring with the hotsync software running.
Are you using the correct cable. You need a NULL modem (crossover) cable. A normal modem cable will not work.
Next I would double check my hyperterminal settings using
this link. Perhaps you have flow control turned on?
Let us know how you get on....
Peter