Are you still having problems with this ?
I saw a can of this at my local frys store sells for around $12
http://www.mgchemicals.com/products/841.html
Reduce or Eliminiate EMI / RFI Interference
A general purpose EMI / RFI shielding spray for use on plastic electronics enclosures. Consists of a tough, durable acrylic base pigmented with a high purity nickel flake.
Shielding effectivieness: One to two mil coating provides 40dB - 50dB shielding across a frequency range of 5 to 1800MHz.
Surface Resistance approx. 0.7 Ohms
Dry time: 10 minutes at room temperature
Recoat time: 5 minutes
Excellent adhesion to most plastics
Available in both liquid and aerosol
Tested as per IEEE Std. 299-1997
Underwriters Laboratories Recognized File No.: E202609
Liquid version available for dipping, brushing or spray gun applications.
Thinner is available for adjusting the viscosity
Thin or clean with part #435-1L Thinner/Cleaner
NO CFC 'S, NO HCFC'S, Ozone Friendly