R help - Jul 2005 - about confounded variances in NESTED and SPLIT PLOT designs

All R users

We observed that for the NESTED DESIGN there is a junction of the 
variable effects randomic that impede the separation of the values of 
these variance components.

Does this also happen in the SPLIT-PLOT method?

Is there junction between main plot error and replicate error?

There is a junction among the main-plot error and the replicatas that 
would impede the determination of these components separately? Is there 
the same effect for SPD?

How to simulate data with values control for each error contribution?

Thanks a lot

Kleber Borges and Jo??o Bort