Arctic Silver is a fine product, and they have solved their problem of electrical conductivity with the production of their AS5. But, the earlier products did have some trouple in that area.
http://www.cluboc.net/reviews/thermal_paste/arctic_silver3/index.htm
Negligible electrical conductivity.
Arctic Silver 3 was formulated to conduct heat, not electricity. It is only electrically conductive in a thin layer under extreme compression. (While much safer than electrically conductive silver and copper greases, Arctic Silver 3 should be kept away from electrical traces, pins, and leads. The compound is slightly capacitive and could potentially cause problems if it bridged two close-proximity electrical paths.)
http://www.cluboc.net/reviews/thermal_paste/arctic_silver3/index.htm
Negligible electrical conductivity.
Arctic Silver 3 was formulated to conduct heat, not electricity. It is only electrically conductive in a thin layer under extreme compression. (While much safer than electrically conductive silver and copper greases, Arctic Silver 3 should be kept away from electrical traces, pins, and leads. The compound is slightly capacitive and could potentially cause problems if it bridged two close-proximity electrical paths.)