Weirdest Fault

After saying in another topic how good things were sounding...

Beat this for the weirdest fault ever!

When recording vinyl to a cassette via the '52.

When I take the record off the deck, there is a static 'pop' and ..

The amp goes into Mono on listen and decides to Mute the recording source and change it something other than phono! No touching the amp or the remote.

Not just once, but several times in a recording session!

I suspect it might be a earthing thing.

Any other weirdness out there ? Or ideas how to solve this?

David