I have tried unsuccessfully on two fresh installs to attach m4a files. Maybe it is the way I am setting things up so I wanted to ask if anyone has any experience with attaching m4a's or maybe if someone can and let me know the settings with media manager... I don't think that is the problem but maybe... if others cannot attach them either, I will put in a bug report.

My results from the admin side:
1. attach the m4a (or select from server) - this seems to work fine
2. Save the item
3. look at the attachment tab - there is an attachment there but the fields are blank.
4. The actual file is nowhere on the server - it is like K2 deleted it???

* adding to bug database I guess...