I have an F900BT that I ordered the 3.0 software from Pioneer for. I got impatient and put on the X910BT software that was posted to this site. Since then I have been having problems with my unit. I want to upgrade to the Pioneer software, but I know I need to revert to 2.006. How do I proceed?
Hi
I will post my experience with just such a process, as I also could not wait and loaded the X version prior to receiving the Official version.
"Disclaimer" I am not saying this is the preferred method an am sure others will commit on my method but it worked just fine and I am up and running on the Official version now.
I first searched this forum and found others in same situation or similar and noted that I needed a backup copy of which I did not do before upgrading the first time and located a user that was kind enough to allow me to download his backed up version ( another gsxr 1k).
After I downloaded his backup I copied it and all subdirectories to a SD card (was a little over 1gb) I had a 2nd SD card that I had the testmode software on already, but if you do not have it just do a search here and you will find it.
Booted unit with testmode SD in and system came up in Windows CE, using file manager I went into the directory of My Flash Disk and deleted all files and then placed in the 2nd SD with the backup files and copied all files/directories under My Flash Disk.
Took SD card out and turned off and back on my unit, which at this time it just went to Splash screen and stayed there 
Then for the heck of it I placed in the #1 SD card of update and reset unit, booted off the SD card and deleted files and copied files (basic upgrade) but again when I power cycled unit it booted back to Splash screen and stayed there not to Top Menu like it was supposed to per instructions. 
Again I just inserted 2nd SD into unit and power cycled unit again, then booted off of SD and showed device number and went online and got my pass-code.
After I entered the pass-code it went through entire install without any issues.
Only complaint I really have was that on 2.06 my microphone and VR was great even driving with the top down, but since the X version of 3.0 and even now with the official version loaded the VR is crap and can not even use it to search for a song or dial a phone number.
Hope this helps a little.