Relay G30 and Spector Euro 5 Problems

Just picked up a Relay G30 and am having problems using it with my Spector Euro 5.

First of all, the bass:

40TW combination single/dual coil pickups switchable via push-pull knobs. Spector Tone Pump Preamp.

I'm hearing what sounds like high piched RF whenever I use the Relay G30 and the Spector. I was told on the Line6 Website that my pickups are acting like antennas and picking up RF, which is being amplified by the Tone Pump Preamp. Same thing happens wherever I've tried - home, rehersal, etc.

I tried dialing back the output of the Tone Pump, but that didn't work. Tried shielding the cavity cover of the bass with copper tape as a jerry-rig type job, but that didn't work. I'm pretty much led to believe that the Relay model with high-powered EMG pickups on any bass might be a bad match.

And I did try every channel. Same thing on all.

Any thoughts? And please DO NOT suggest that I return it and get the G50.

BTW - works fine with my passive Warwick and my active Yamaha John Myung 6 string.