[Haskell-cafe] Potential problem with AC-Vector-Fancy package

Is anyone maintaining the AC-Vector-Fancy package? I haven't had a reply from the latest maintainer (Andrew Coppin) on Hackage, so I thought I'd open it up to cafe: I think I have found a problem with the union function: If you look here: http://hpaste.org/49889 You will see that line 4 gives a different result to lines 6, 8, 10; this shouldn't be the case because union is commutative.