I'm having a strange issue. My Verizon DSL line drops out when a storm is moving in; before the rain even starts. When I hear a clap of thunder in the distance, it immediately drops and then will resync until the next rumble. A tech has been out three times and has changed the pair going to the CO all three times. I'm at a loss, I've checked the grounding where the equipment is plugged in and it all appears to be good.