Could be a non-Ford belt issue. I replaced mine last summer w/ an aftermarket one from AutoZone...made my car sound like it had a supercharger (which would be nice if it really did!). Replaced it w/ a Ford belt, noise gone. Might be worth a shot.

1999 Contour SVT #1966/2760, Silver Frost/Midnight Blue Koni Kit, Mille Miglia MM-S rims, B&M shifter, Stazi mesh, SFCs, optimized Y-pipe & TB, SS break lines, K&N drop-in, Infinity Kappa speakers, MTX amp/sub