Mat,
we did get the e-mail, and replied. Unfortunately Ahmed forgot to ask you to include a link to this forum thread in your e-mail, so one of my colleague's replied to your e-mail (it was about 2.5 hours you sent your message, in case that helps you locate it) that you could manually adjust the lip sync in XBMC. Without having seen your forum thread, he didn't realized that you'd covered this and a lot more already.
Can you provide the exact sequence of XBMC add-ons/streams/media hosting provider that you click on when the audio/video sync is lost? Even if it happens on everything you try, just let me know one specific example, and I'll match the scenario on my Q7.
If the video streams work properly all the way through, on my device, we know it isn't the infrastructure (which is out of our control) that is to blame, but your individual hardware unit.
If it is JUST your device that behaves this way, I'd first suggest a recovery menu based factory reset (see
https://droidbox.co.uk/blog/how-to-access-your-droidboxs-recovery-menu/ , select Wipe Data/Factory Reset, and reboot when the process has completed). Once you've arrived at the Android launcher's homscreen, leave it 20 minutes (no clicking or rebooting), then check if Frodo XBMC is any better behaved with Lip Sync (don't forget the DroidBOX Wizard Q7 device pack obviously). If it misbehaves uninstall it and install the Gotham XBMC build again, and test.
If the sync issues remains, please send us another e-mail with
http://www.droidboxforums.com/posts/907 somewhere in the message, and mentioned Chris stated this was a REPLACEMENT scenario, not REPAIR. btw, the order number you included last time was actually a generic item number that is for all Q7s, if you look in eBay's purchase history, you should find a nice long number that has that item number, and then some further digits.
Moving on to VideoMix, we originally provided a copy of VideoMix Pro with an older firmware, but it turns out that this version no longer works reliably, and as VideoMix is free and the updated version works, this is the one we now include. I'll make a note to update the listings, thanks for the reminder.