Video card oveheating in Precision T5400 desktop but not in Vostro

Hello,

I have fanless Radeon HD 5700 card which I successfully used for more then a year in Vostro desktop. I recently moved card to Precision T5400 Workstation and it fails intermittenly due to thermal shutdown while playing Age of Empires 3 games on high resolution.

I don't think there is enough airflow in central compartment to cool the card. Can I somehow make central fan spin faster or what are my options?