200T oil pressure problem

[randrews@post.cis.smu.edu (Robert Paul Andrews)]

My dad's oil pressure in his 200T has just gone screwy.  The shop ust replaced
the oil pressure switches figuring that was probably it, but no.  After
the car is warm, oil pressures drop two low, and the warning light sounds.
I am not sure waht the gauge says, but cold, the car is fine. BTW-the oil
just got changed, and no it isn't low on oil either.  Any ideas what this 
could be? THanks!
Rob
randrews@post.smu.edu