[Haskell-cafe] Why are new releases of libraries required for every GHC release?

Some recent comments suggested that every time there is a new GHC release, there needs to be a new wxHaskell release (or insert name of other library here) to work with it. This seems to be true even for minor upgrades, like 6.4.1 -> 6.4.2. Why is this? Does GHC break binary compatibility at every release? Is this avoidable? This makes using Haskell unnecessarily hard compared to other platforms.