It just so happens new versions have other issues.
You're not seriously trying to tell me that FMOD has had broken .it support for -- what? -- a year or so now? Anyone who has used the library itself can tell you that it certainly hasn't.
Look: I buy a programming language, a feature of which is .it playback; The language's author "updates" it and suddenly that feature no longer works; Conclusion... the language's author broke the language's feature. The end.