Signal lower on 99, 103 but still high on 101, 110, 119

Greetings,

We had our system installed about 6 months (winter). It's a Slimline 5 SWM setup. The installers told us that we would get a good signal at the time of the install, however, that we would need to cut down 2 trees before summer got here. Well, now summer is here and the trees are in full bloom. However, I have noticed that the 101, 110, and 119 satellites are all still getting all 90's (mostly 95-97)... while the 99 and 103 are now getting anywhere from 68-83 (mostly low to high 70s). At first I thought maybe the trees are in the way now... but then after doing some research, it seems as if the 119 bird is the lowest of them all. If it's getting high 90's, maybe the trees aren't the problem and the dish just needs slightly re-alligned. We had just had the area bull dozed about a week or so before DirecTV did the install. Maybe the ground settled/shifted. Anyways, it would be a really big deal to cut down the 2 trees in question. Is it possible with the 119 being so strong, than the trees anden't the issue at all? I would hate to cut them down and then find out it's not the problem. Any comments would be greatly appreciated.

NOTE - I have a Supper Buddy satellite meter (from work), but I don't think it works on the 99 and 103 birds?

-Thanks