[BioC] Problem of using Affy!

[Zeny Feng]

I am trying the software affy. I follow the user manu of affy and put all the
 cel files in the working directory. But when i use the rma command, there are
 many warning messages. for example,

 cannot open: HTTP status was '404 Not Found'
 Note: http://www.bioconductor.org/CRANrepository does not seem to have a valid
 repository, skipping

 I check the web: http://www.bioconductor.org/CRANrepository
 it was really "404 not found".

 The attached file has a print out of the warning message.

 Can you tell me what should I do in order to use affy?

 Thanks a lot!

 Zeny