[G a f f e r]

I have a panny ae500.
I have recently noticed that the image has a slight 'shimmer' to it. It's difficult to explain, but it's like the brightness is fluctuating ever so slightly (but rapidly and noticeably). To confuse things even further, it's not always there and when it is, i'm not sure if it's with certain discs/scenes. I just notice it sometimes and at others I don't. Someone suggested it was the low lamp mode and A.I. in high lamp mode made it go away, but this hasn't worked (besides, i think it looks better in low lamp ).
Going to the flicker adjust menu and red, green and blue settings are completely stable. Switch back to the film and there's that shimmer again. .
I think it might be a mains problem. I live in a flat where the power in a standard socket isn't what you would call stable (the red light 'on' led on the mains block also flickers). So I bought a surge suppression/RFI suppressor mains block and have plugged the projector into this (along with console, dvd player/amp, sub, valve amp, cd player, md player - but only two of which are ever on at once). This hasn't cured the problem.
Q: does anyone agree it sounds like a mains supply problem?
If so, how can I verify this?
Is there a cheap solution (short of spending £500 on a mains conditioner / iso sub psu......in fact closer to £20 would be a good limit )
Thanx for any advice.
PS RFI suppression ferrite rings on the mains/component lead also had no effect.

[Adrenochrome]

Do you have your power cables away from your video cables?

Adrenochrome.

[G a f f e r]

Yes.

although cable positioning seems to make no difference either.....i'm well and truly stumped.