[BioC] trouble using GCRMA

[wong]

Hi all,
I just started to work with gcrma to get expression indices for
microarrays of yeast 2.0.
The error occured when I tried to make expression summary with package gcrma.
Some of the R code and error information are showed below:

> Data<-ReadAffy()
> est<-gcrma(Data)
Adjusting for optical
effect................................................Done.
Computing affinities.Error in xy2indices(p$x, p$y, cdf = cdfpackagename) :
        unused argument(s) (cdf = "yeast2cdf")


I'm using R-2.5.0-win32 and gcrma_2.8.1. I guess I am doing something
wrong here but I do not realize what.
Any help would be appreciate


wong