[BioC] error following cluster example

[kfbargad at lg.ehu.es]

Dear Users,

I am following the example on Lab 5: Cluster analysis (June 2003) with 
my own data.

I have filtered my expression set as shown on the example and I get 
the following

> sub <- genefilter(X,ffun)
> sum(sub)
[1] 1124

I save this subset of genes and then log transform it. But when I type 
the next command I get the following error:
> X <- X[sub,]
> X <- log2(X)
> RawDataSub <- Raw.Data[,sub]
Error in Raw.Data[, sub] : (subscript) logical subscript too long

Why do I get this error?? 
Also, if I have stored the subset expression data as X, why is Raw.Data
[,sub] using [,sub] again? I don´t really understand this step, if 
anyone could explain its purpose.

I´m running R 1.9.1 on an XP computer

Thanks a lot for your help

David