Com port locks up computer

Hi,

I've implemented the TAP 1.8 communications driver to communicate with an
Ascom wireless telephone system. The Ascom hardware is connected via two
serial ports.

Through testing however, I'm noticing that my computer freezes
(temporarily). This is consistently generated when I pull the power plug on
my Ascom hardware. If the power down doesn't create a freeze, then a power
up may create it. In order to get out of the freeze, unplugging the serial
cable at one end usually solves the problem.

Is there any way to prevent the computer from freezing? Is there something
happening at a hardware level that would cause this? I'm running Windows
2000 Pro. If you need additional details, please let me know.

Thanks in advance,

Chris