I tried the standard sample rates that the file could be. I’ve had similar issues where a file header has the wrong sample rate than that the file was currently in. The way I solved that before was some combination of importing the file into a project with a given sample rate without allowing Cubase to convert the file. Then Changing the project sample rate and allowing Cubase to convert it, which treats the file as the current project sample rate. Very confusing but that normally works.
This time that solution doesn’t seem to work. I think the likely answer is to use the ‘process>re sample’ option with the correct % value. I worked out the % difference in length of the two audio files. This produced a closer match to the original, however it still went out of sync. But… (it may be my imagination) it seemed to take longer before the sync issue became apparent.
My question is now… How could I go about working out a closer % for the re-sampling? I’ve uploaded the two audio files as this may make it easier for you to understand. You can download the WAV files here: https://drive.google.com/file/d/0B4kl1vEOrG7lZXNfVmEyb205VXM/view?usp=sharing
Thanks for you patience everyone!
P.S. Things I know: Video is at 25fps with audio 48k, Additional WAV is at 44.1. I believe both audio are in 16bit.