Hi all,
just to share my experience:
Story/problem :
I bought a 32 gb flash stick and put all my mp3s on it... of course the Avic F900BT couldn't read it.
Then i got a 1 gb flash stick, put some files on it, and this was working ok.
Before drivng a long trip, i ve added a few mp3s to this 1 gb flash card.. but was disapointed when during the trip i wanted to play the music on it : Either it couldn't see the 1 gb stick, either it was seeing it, but showed it as empty :S
So i've spent like 2 hours in the car when arriving at destination, with a laptop to help identify the problem.
Now not only i'm able to read the 1 gb stick (FAT16), but also the 32 gb stick (FAT32) !
I did noticed that the few times it was seeing a stick connected and showed it as empty, the "video" button" was actually active and i could press on it (that meant it DOES know the stick is NOT empty and it knows it has also video files on it!). That gave me the hint to the solution :
Solution :
the avic first tries to read all the files that are in the ROOT directory of the USB/SD. If it has a file that it cannot read (see the link to this file at the bottom of the message), it will BUG and show the card as being empty or even not seeing any USB/SD connected !
So i didn't put any file at the root of the USB/SD and put all the files in a few folders : what a surprise ! NOW it could read even my 32 gb stick !
(but of course when reaching the folder containing the "crashing file", the avic was seeing again all the stick as being empty :S
Anyway, i managed to identify the simple mp3 file that the avic can't read and then bugs .
Hopefully Pioneer will correct this bug on a future firmware update and will display "unreadable file" instead of bugging the whole USB/SD connection until the next reboot and making all the stick suddenly unreadable.
for info, i have the firwmare 1.0019 (EU version).
If one of you want to try out this bug and see if it's bugy also on US version and/or older firmware, here is the file (btw, it s read w/o problem on any computer):