In Ubuntu 12.04 -
When I drag .mp3 files from Banshee 2.6 to my Mac-formatted iPhone 4s ios5.1:
a. Banshee says it's syncing with the phone, updating the media database, and the filecount on the phone is incremented;
b. The files show up under the device in Banshee and I can play them;
c. I can see them on the iPhone in a file browser;
d. I can navigate to the iPhone filesystem in a terminal and create a file, so I know I have write permissions.

When I disconnect the device in Banshee, it again tells me it's syncing the phone and updating the media database, but I can't find the songs on the phone in iTunes - they are not there when I reconnect the phone to my computer.

Am I just being deceived by gvfs?

I haven't been able to find a recent post indicating the status of syncing ios5.x devices with Banshee, RhythmBox, etc... Can someone tell me if this should work?

Also, I wonder if my iPhone needs to be formatted/initialized by iTunes for Windows, since it has been managed on a Mac? I solved a syncing problem with an older ipod classic which had been managed by iTunes on a Mac, by re-initializing it under iTunes for Windows - perhaps an hfs+ issue.
Thanks for any help.