Computer goes to Hibernation

[Mack]

I moved my computer. When I tried to attach a terminal
node controller to a serial port, the computer would go to
Hiberation mode and shutdown. When I disconect this
hardware the computer boots normally.
This hardware had been working ok before I moved the
computer.
I am running Windows XP Home Edition with Service Pack 1.
Please send any reply to:
Thanks for your help.

Mack