Wildcard syntax

Hi, I have base == 4.0.* in my hlint cabal file (http://www.cs.york.ac.uk/fp/darcs/hlint/hlint.cabal). Does that require Cabal 1.4 or 1.6? Apparently 1.2 fails to parse it, but with a cabal-version >= 1.2 declaration I don't get any warnings from Cabal 1.6. So what is the minimum verison for the version wildcard, and why doesn't cabal warn me I got it wrong? Thanks Neil