Hi. I'm still having problems with the uvector package. I have an IntMap (UArr xxx) data type, and I want to serialize it to disk, in binary format. I'm using the uvector package from http://patch-tag.com/repo/pumpkin-uvector/home The problem is with missing instance declarations, for Hyperstrict data type and Data.Array.Vector.UArr.UPrim. For the former, the instance is simple, but for the latter I have no idea about what to do. The full error message (GHC 6.8.2): No instance for (uvector-0.2:Data.Array.Vector.UArr.UPrim (Word32 uvector-0.2:Data.Array.Vector.Prim.Hyperstrict.:*: Word8)) arising from a use of `encode' at bin/process-data-1.hs:72:18-36 Possible fix: add an instance declaration for (uvector-0.2:Data.Array.Vector.UArr.UPrim (Word32 uvector-0.2:Data.Array.Vector.Prim.Hyperstrict.:*: Word8)) Thanks Manlio Perillo