Please Help - Wireless Router drops ADSL and LAN when outside lights are on. Any Solutions?

We have recently put the Christams lights up outside and the kids are
really excited.

Unfortunately whenever they are switched on the ADSL connection dies
followed by the LAN (both wireless and wired connections)

I have traced the cuplrits to two 10 metre rope lights. If I unplug
them then everything works fine (albeit with a couple of CRC errors
each minute).

My question is: Are the lights affecting the Router? Telephone Line?
or Wireless Connectivity?

Is their a way I can shield the equpment from the interference?

The router is a 3Com OfficeConnect Router with built in ADSL Modem)
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cheers

Harry