H'mmm. On the face of it, it does indeed sound like excessive leakage current there somewhere. It could indicate a defect of some kind. Or perhaps the thing just draws a heavy current anyway, upsetting (or confusing) the LIM. Odd, though, that you get comfortable readings with your electrical safety tester. You may find that you need to provide a special (that is, standard, "earthed") power outlet in the theatre just for this unit (as sometimes needs to be done for other items, like mobile C-arm x-ray units, for example). But as the unit is still "new", perhaps you should first of all seek the opinion of the supplier!
