llvm dev - May 2012 - [LLVMdev] LLVM Rc3 sources?

Hello,

Trying to build llvm & clang 3.1 rc3 from official tarballs, I noticed 
that rc1 provides llvm-3.1rc1.tar.gz which is not provided for the rc3.
I am looking here:
http://llvm.org/pre-releases/3.1/

Any special reasons for that ?

Thanks,
Sylvestre