Berry...
Two things come to mind. First, I'm not sure not tasting oak is a bad thing. (See my last paragraph.)
Second, my "read is this: The dosage and time indications on packages oak are generally geared toward grape wine which, because of the seeds and the fact it is often fermented with stems, starts out with a bit more tannin than most fruit wines.
I only make wine from grapes, but I take the time indication on the package not as a maximum time, but as a good time to begin tasting. And I generally keep the cubes in until my wine starts to taste as though its been a bit overoaked, because I know its going to spend another year or more in the bottle beforeI start to consume it.
At that point (12 to 24 months after bottling), there should be no "oak" taste at all, but a pleasant, subduedvanillin flavor well integrated with all the others that make wine so special.
Edited by: jshuey