TCAS detects own plane

Has anybody else has the problem whereby TCAS detects your own aircraft and constantly gives aural 'TRAFFIC' alerts?

It doesn't matter which aircraft I am flying, I see the same behaviour in the Feel There, LDS and the NGX. I tried changing the FSUIPC identifier inside FSX but no effect.

I've searched but not found an answer.

Appreciate a fix for this most annoying problem!