[Haskell] Fast Packed Strings Question

[Dominic Steinitz]

After a lay off from Haskell for a few months and preparatory to Hac 07, 
I thought I had better check my laptop was appropriately set up. 
However, I encountered the following:

C:\Documents and Settings\Owner\crypto>Setup build
Preprocessing library Crypto-3.1.0...
Preprocessing executables for Crypto-3.1.0...
Building Crypto-3.1.0...

Data/Digest/SHA1.hs:36:17:
    Could not find module `Data.ByteString':
      it was found in multiple packages: fps-0.8 base

What's the story with fast packed strings these days?

Is it now part of base and I shouldn't have installed it? If not, can 
someone remind me how I hide the module in base?

Thanks, Dominic.