Added missing imports

Ignore-this: 95af5906ff14c1d6b85d5c03817deea0

darcs-hash:20100121125257-1e3d8-7a37aa691d3cbfbd2da820818686be267ca8adce
Fixed typo ErroCode -> ErrorCode

Ignore-this: c081f0c0a3bb0f5ad3a42d83142da85d

darcs-hash:20100121125309-1e3d8-5c1d63b0c9ea2364b337e138d78a34412f6846f7