Essentially, you want to ruggedize this component. Various adhesives could work great, depending on the source of the energy that is causing the solder connection fatigue. So, what are your looking to: * Rigidly bond the component to the board? * Absorb the vibration / twist / what ever from the board to the component? * What?
If we knew more about your situation, we might be able to help more.
What�s your thinking on using dampeners or stiffeners on your board to reduce this problem?
I reviewed a very good book on vibration in the SMTnet Newsletter, fairly recently. Look at Steinberg "Vibration Analysis For Electronic Equipment� Wiley Interscience.