Poor Sat Reception
 

I am having alot of signal dropouts with my XM. It seems that if there are alot of trees close to the edge of the road with branches hanging over towards the travel lanes,not actually over the car,the signal will drop out for a second or 2. The antenna is mounted on the roof above the rear view mirror,and about an inch or less from the windshield. I read somewhere that there should be 3 inches of metal on all sides of the antenna. Do you guys think that my problem is as simple as moving the antenna further back from the windshield towards the center of the roof a few inches? My signature show the gear I have. The antenna is the small magnetic antenna for XM that came with the pioneer box.
EDIT: Looking at the manual for the Pioneer Sat Box,it says to mount the antenna more than 6 inches away from the edge of the roof. I wonder if this much space is needed...

I install them on the edge of windows all the time and have no issues at all.

I had the antenna moved back some and now have an ugly black strip covering the wire. The shop seemed to think that it would not make a difference,but I pointed out that the manual says it should be more than 6 inches away from the edge. I also read on the XM site that there should be at least 3 inches of metal on all sides of the antenna. I will have to see if the reception/drop outs are any better.