What are your 99c readings? Basically anything under 89 will fail, which doesnt mean it wont work, just that something is making the signal drop (weather, cable, distance, connectors)
There is a huge problem with the Slimline5 LNB's and HD receivers right now. Still have not gotten an answer to what is causing it.
What we have done to get the receiver to work.
Go into satellite setup and chose 18x20 as the dish. Remove the BBC's, the system will still come up with some kind of error. Just go to the continue and let the receiver download the program guide info. When you get back to a channel, go back and re-setup with the slim 5 and put the BBC's back on. It may or may not come up with errors, but the receiver should work.