[BioC] Question about heatmap

[Giovanni d'Ario]

Hello everybody
 I'have a general question about the heatmap function. I'm clustering an 
expression matrix with different dissimilarity measures. Correct if I'm 
wrong but if I want to cluster the columns I have to scale the rows to 
bring the genes to a common range, and this is apparently the default 
behavior of heatmap (according to the option scale="row"). So I expected 
to see different dendrograms,  setting scale="none", but there's no 
change. It seems that the scaling only affects the plotting but not the 
generation of dendrograms. Where's the mistake?
Thank you in advance
Best regards

Giovanni d'Ario