There's something else very wrong when going from 3.4.9 to 3.4.16.
I've done it on two machines here, one the AMD-450 server (64-bit),
and the other my main notebook (Core2duo 32-bit-PAE).

Both systems feel much more sluggish than usual with 3.4.16 running.
Reverted them both back to earlier kernels (3.4.9, 3.4.4-PAE),
and the usual responsive feel has returned.

Vague, I know, but something bad happened in there somewhere.

Cheers