I've got my dish mounted on a wooden fence and I've noticed that every 2-3 years I need an alignment. Also, my neighbor has a maple tree that is growing steadily and I think it's interfering a bit. A few months ago I noticed signal degradation especially in the 110 and 119 satellites (119 was down to around 70% and 110 was at zero), but also a couple of my 99 transponders were at 77%..when performing a system check I would get an error message saying there was a dish alignment problem. But none of this was causing me any issues until the last couple weeks. I had 2 HR21's..and one of them was having real problems with picture quality and it would get very temperamental when watching recorded shows to the point it was becoming unusable. But the other HR21 was working fine. So I called and they sent out a tech yesterday. But before he tried realigning my dish he swapped out my Slimline 5-LNB with a 3-LNB (still the same dish..just new LNB). He told me that I would no longer see satellites 110 and 119..but 119 is Spanish programming and 110 is not in use so it's no loss for me... I was a little surprised he did this even before trying an alignment first... but in thinking about it I guess it's better in my situation (with my wood fence/tree issue) to have the receivers looking at fewer satellites to avoid slow processing times when signal problems arise with 110/119 if I don't even need them. He ended up replacing one of my HR21's with an HR24...I am very happy about that..the HR24 is so nice and fast. After the alignment all of my signals are back in the high 80's-mid 90's where they should be... minus 110 and 119. Actually eliminating these 2 satellites has made my remaining HR21 perform a little faster (at least it seems like it).