Do you have unshielded cable runs and happen to live near a radio tower? If this is the case, you might be getting some RF interference. This is certainly more likely than getting any bleed from the 2nd zone as I've never seen anybody post that problem on this forum.

Edit: Unferth, I think you're right. It's more about the shield than the length. Though longer lengths of unshielded cable can get nasty.

[This message has been edited by Jason J (edited February 26, 2004).]