Sorry, I think I confused you a little. The dish [azimuth-left/right] will point directly at the satellite, just on a offset dish, with the LNB on a arm at the bottom of the dish verses a prime focus dish with the LNB mounted on rods in the center of the dish, the signal comes in at an angle higher and the dish will look like it's aimed at a spot lower than what it actually is, elevation-wise, up/down. So if the dish looks like it's pointing into trees, it might still be all right because the signal comes in at a much sharper angle and not directly straight into the dish. I think a 40'' Fortec is offset and would be the same as the Slimline in the sense of setting it up, not 100% percent sure because I've never had a Fortec dish, yet.
One thing I forgot to mention is to check if your mounting pole is plumb all around. On a fixed dish, if it isn't, you can still set it up but it's much harder if it's not plumb. You can use a level, or an angle scale like this if you have one, this is what I use:
Amazon product ASIN B00004T807
But a level will also work fine, put it on all four sides of the pole and make sure it's not leaning one way or the other, if it isn't plumb, adjust it so it's plumb and it'll be much easier to setup.
I think you probably were going about it right, maybe just moved the dish too quickly. Set the elevation of the dish [the scale on the side of the dish mount] to the elevation setting from Dishpointer. Entering just Florida for a location on Dishpointer, I get 53.4 degrees for 97W, which may be a little different from what you get when you enter your exact address.
Looking at Dishpointer, it says a skew of 27 degrees for Florida on 97W. If your dish is like mine, standing behind the dish and looking at the back of it, on the piece bolted directly to the dish, you should see a scale and three bolts that you can loosen and adjust the skew by turning the dish [not moving the whole dish and mount, only rotating the dish and LNB arm, nothing else!. 90 is the zero point, here in Ct the skew for 97W is 24 degrees, the optimum for my dish was 78 degrees, so 27 would probably be around 75 or so on the scale.
Then with the dish loose on the mounting pole, just move the whole dish and mount left/right to the azimuth setting from Dishpointer, I get 210.8 degrees true and 216.6 degrees magnetic for azimuth by entering just Florida for a location on 97W. Again, you'll have different numbers when you enter your exact location. Point the LNB straight at that point, using a compass, the magnetic azimuth number should be closest.
If your Slimline is like mine here with an adjuster bolt on the bottom of the mount for fine tuning the azimuth, you can lock the dish down tight onto the mounting pole at this point and then use the adjuster to move it back and forth to try and find the sat. I'm not sure if all Slimline dishes have them, but mine has a adjuster bolt for fine tuning azimuth and one for elevation and it makes it real nice for setting up. If yours doesn't have the adjuster bolts then you'll have to snug things up but leave everything loose enough to move it to try to lock the sat. I'll try to post up a few pictures tomorrow if I have the time, so you can see what I'm talking about better and see if your dish is the same as mine is.
Sometimes when you tighten the dish down onto the pole it'll knock elevation and stuff off a little too.
Once you're at this point, probably make some marks with a marker on the adjusters, or the elevation scale and mounting pole if your dish doesn't have the adjusters, so you can return to the starting point if you need to and then just try moving it a little bit at a time on the azimuth and/or elevation to try to lock it in. The position of your LNB could throw you off too, but if you got it where the original one was, nice and straight and at the same depth away from the dish, I would think you should be all right with that.
