I'm very new to Haskell and am trying to write a "real" program to motivate myself to learn it better (so far I've only gotten through Project Euler problems after reading LYAH and most of RWH).  I'm using Taglib (https://github.com/taglib/taglib) to read the metadata from a music file and print it.  I have a struct C-side (with C linkage) serving as the bridge between Taglib's C++ and Haskell's FFI.  A small demo program (compiled with gcc and linked against the C++ object files) gives the correct results, but Haskell is weirdly only getting some of it right.  Specifically, the C string fields are working but ints are not.