[BioC] error creating new exprSet

[kfbargad at ehu.es]

Dear list,

I tried to create a new exprSet from my filtered Affy genelist using R 
2.3.0 with
affy "1.10.0"
simpleaffy "2.6.0"
genefilter "1.10.0"

and I got the folowing error:

good.eset = new("exprSet", exprs = good)
Error in validObject(.Object) : invalid class "exprSet" object: number 
of exprs columns different from number of pData rows

But
dim(good)
[1] 7420   20
dim(pData(data))
[1] 20  1

I moved then to R version 2.2.0, 2005-10-06
affy "1.8.1"
simpleaffy "2.4.2"
genefilter "1.8.0"

and the very same commands gave me no error.
>good.eset = new("exprSet", exprs = good)
>good.eset
Expression Set (exprSet) with 
        7420 genes
        20 samples
                 phenoData object with 0 variables and 0 cases
         varLabels


Have I missed some critical changes in the new versions of the 
packages?