I've just today set up my v3Arcade, everything seems to be working perfectly except that scores from the Mochi games aren't being added to the VB leaderboard.
The scores from the default games provided during installation are adding perfectly with no problems.
No error is displayed to inform why the score hasn't been saved. The score is submitted to Mochi but never to the VB leaderboard.
The site never attempts to redirect to the score page at the end of the game either like it does the default included games.
I've got the crossdomain.xml in the root folder.
I've set up all the details from your FAQ exactly as specificed and been over it many times to be sure.
I'm using the latest version of v3Arcade obtained from Vbulletin.org on Vbulletin 4.1.6.
If you can shine any light on why its not working that would be great.