QNX4.25G Hangs when the Power Source switch

QNX4.25G mainly hang when the electric power cource of Fujitsu NSeries notebook switch from AC Adapter to inside battery or from battery to
AC Adapter back. But some time it continue to work properly in fiew seconds.

How can I set electric power source switching stability for QNX4 OS on notebook?

Thank you.

Are you sure it is hanging? I have problems with ibm laptops. Sometimes when power switchs (battery <-> AC), I lose my keyboard. I can still access it from the network. One suggestion I got was to play with the BIOS options to disable some features for battery mode (steepstep technology? cpu optimization ?)