In general you should avoid performing multiple calls with aov
and rather use a mixed effects linear model.
You can find several examples in this post by Paul Gribble
I often use the nlme
package, such as:
require(nlme)
model <- lme(dv ~ myfactor, random = ~1|subject/myfactor, data=mydata)
Depending on the situation you may run in more complex situations, I would suggest to have a look at the very clear book by Julian Faraway "Extending the Linear Model with R: Generalized Linear, Mixed Effects and Nonparametric Regression Models".
Also, you may want to ask on CrossValidated if you have more specific statistical questions.