I exported 4:2:2 1080i .mxf files from Final Cut thinking it would be a piece of cake for Avid.

Apparently not.

The XDCAM transfer utility talks to FCP only, so I´m wondering what to do next. The Avid editor asks for .bin or .avb files (probably wants the original files).

Any solution to this?

Yes. U need to upgrade to version 5. V. 5 AMA should link your mxf files. Another option with v 5 is export out ProRes Quicktime from FCP. AMA links to any quicktime file without transcode.

Just to verify: The editor (client) needs to update to MC5?

First, the MXF files out of FCP are NOT compatible with the MXF files that Avid creates. So that's the first problem.

Second, V5 of Avid MC will NOT just import (via AMA) MXF files from FCP. Those files need to be .MOV for that to work over AMA.

Third, you cannot give a .AVB or a .BIN to an Avid editor from FCP. Those are Avid specific and Avid only.

It sounds like the two of you really need to get together and discuss and learn how to work back and forth between Avid and FCP.

If the Avid editor wants compatible files, then install the Avid DNxHD codec onto your Mac, and export DNxHD .MOV files for him. Those will fast import into the Avid system and he'll be just fine. If the Avid editor has version 5 of Media Composer, then you can export nearly ANY quicktime file and he will be able to read it, but DNxHD encoded .MOV files will make his life easier down the road.

If you want to go back and forth from FCP to Avid, do NOT use .MXF files.