clang_createtranslationunit not working (libclang on Windows)

In the 3.6.1 build on Windows. If I keep translation units in memory, every thing works fine.

However as soon as I save a TU to disk and then load one with clang_ createTranslationUnit and call reparse. The reparse fails.

this should work or do I have to do an intermediate step?

Any help would be appreciated.