Are you currently having problems with viewing the above channels on Astro? If you are, this might just solve your problem in the simplest of ways.
Step 1 - Do you own a Panasonic cordless phone? If, yes, is it currently plugged near your Astro decoder?
Step 2 - Turn off or unplug your Panasonic cordless phone.
Voila! Your problem should be solved. If not, call Astro for the technician again.
How did I come to know about this? I have not been able to watch the above channels for a few months. Recently, I got fed up of waiting for it to magically correct itself and called Astro. A report was filed and the Astro technician came to my house a few days later. All they did was turn off / unplug my Panasonic cordless phone and MAGICALLY, I could view Channel 412 & 511 again. I asked for clarification and the technician stated that many people had complained about this and most of the time, it has been because the frequency of the Panasonic cordless phone is interfering with the Astro frequency for those channels.
However, I have had this cordless phone for 4 years and never had trouble viewing the channels until recently. So the technician guessed that Astro could have changed certain frequencies (can't explain more since I don't know anything about this satellite stuff!). Apparently, the technician said one of the customers requested that Astro replace his Panasonic cordless phone since it wasn't his fault that the frequency was interfering with the Astro channels. I wonder what became of THAT request. Hahaha.
So hope this blog post helps some of you having the same problem as us!