phasing issues

I've set up a spare bedroom for recording electric guitar. I'm playing thru a Hughes and Kettner Switchblade 100W combo. I'm using a 3 mic technique. The first is a dynamic SM-57 placed about an inch from the grill cloth, midway between the center cone and the outer edge, pointing straight to the speaker. The second is a ribbon mic (Fathead Ribbon) that no matter where I put it (1"-6" away from the grill cloth), I'm getting phasing. I've also got a condenser mic about 5-6' back to pick up the room sound. When I click the phase switch in my sequencer (Sonar) on one of the 2 close mic channels, the sound thickens up nicely and seems to be acceptable. Is it normal to have to use a phase switch like this? In an ideal world, wouldn't it be better to not have to do that? Any advice would be appreciated.