charsleysa:
If you have the 7390 follow this link to the BETA firmware (no promises on providing a fix).
https://mega.co.nz/#!09tRXLCS!f3XYlXJ-yDLbiXJCLoQv6NVqYYA2gXHM8V19wGpDukM
Thanks mate.. Was able to install this as a downgrade without having to do a recovery and shazam, VDSL sync.
Hopefully it's not too dodgy a build.. Once installed, it lists itself as "06.01-sroemer-build_1209-27067M".
The 6.04 beta from ftp://service.avm.de/Beta/FRITZ%21Box_7390/fritzbox-beta-7390-27435.zip wouldn't install over the top of 6.03.. Said it wasn't valid for my hardware... May try again on top of this 6.01 beta and see what happens (when I have time to fix things).