[BioC] vsn procedure error

[Edmund Chang]

Hi all,
I'm trying out the vsn procedure instead of rma. But i got the following 
error message. What does "ARG" mean?
Must the VSN procedure be used with no background correction?  and why 
is there a warning saying that "multiget is deprecated?
I installed the R vers.1.9.0 and BioC 1.4.

I appreciate all the help that you can give me,
Edmund

 > eset <- expresso(Data, bgcorrect.method = "mas", normalize.method = 
"vsn", pmcorrect.method = "pmonly", summary.method = "medianpolish")
background correction: mas
normalization: vsn
PM/MM correction : pmonly
expression values: medianpolish
background correcting...done.
normalizing...Error in match.arg(method, normalize.AffyBatch.methods) :
        ARG should be one of constant, contrasts, invariantset, loess, 
qspline, quantiles, quantiles.robust
In addition: Warning messages:
1: 'multiget' is deprecated.
Use 'mget' instead.
See help("Deprecated") and help("base-deprecated").
2: 'multiget' is deprecated.
Use 'mget' instead.
See help("Deprecated") and help("base-deprecated").
 >