Dripping faucet ?

[bigdog]

I have a dripping faucet issue with my kitchen sink.
It's a two handle Delta faucet.

In the past, I removed the faucet handle, then the stem assembly, and last the rubber washer and spring in the seating hole.

Had same issue before, and all I had to do was replace with new rubber washer and spring to cure the issue. I did the same this time around, but faucet still drips.

Could the underlying issue be the stem assembly causing the dripping?
Do these stem assemblies ever go bad ?

Thanks!