Are you talking about interference on the Zoom H2 recording, or on a wireless mic system with a seperate transmitter and a receiver? I've never experienced interference while using Zoom H1's but have many times experienced interference when using Sony or Senheiser wireless mic systems. Most often it's a result of cell phone activity (Blackberrys are the worst). If your setup has selectable channels or frequencies, you could try switching to another channel or frequency that has less interference…of course unless you are constanly monitoring the audio signal you won't really know if you have a problem until post production begins.
