Docked T60 Loses Power

[boxerguy]

I'm pretty new to the IBM's, we have just started using them here at work. We have serveral T60's and R60's, question is when docked in both the advance dock or port replicator and the power goes out the system will die, but not completely. You will have to undock, hold power button down then redock and power back up. We all thought that it should fail over to battery power then once power is restored it should resume as normal. We have a system generator that kicks in after 18 seconds so this is a huge problem for us. Do we have a setting that should be changed or is this normal?