I understand that the sling catcher has been discontinued in states, is this because it is unreliable?
I don't know for sure, but I'm guessing that Sling Media was unable to keep up with emerging technologies. Sling Media's flagship product is the Slingbox Pro-HD In the United States. If I remember correctly, the Slingcatcher's maximum output resolution is 1280x540. This is the lower end of the HD spectrum. The Pro-HD's on the other hand could stream as high as 1920x540, but the SlingCatchers didn't make use of the higher resolution. This cause disappointment since the picture had to be downscaled to the SlingCatcher and then upscaled by the television.
Compound that issue and it with all the problems they had supporting various formats and filesystems. It was probably the final straw that broke the camels back. That's probably why you only see the SlingCatcher available in the countries where the flagship product is the Slingbox Solo.
I currently setup one classic and one black PRO-HD in one home in Hong Kong, and another red HD box in another. Three boxes operating over two broadband lines. In UK, I stream the boxes over a sling catcher. Last week I changed my talk talk line to a virgin line as I thought that the 6MB talk talk line is too slow. The fibre optic virgin line seemed interesting at 10MB. But now on my sling catcher the line fluctuates between 130KB to 600KB, and then downs out after 10mins. This didn't happen on talk talk but on talk talk I can get 650KB on a good day, whilst most times is at 300KB.
On the computer, the line still fluctuates but does not drop, only if the line become too too slow. I tried it on both my broadband boxes, and getting the same message and results as I thought it could be my line in HK. What can I do to fix the situation? What could be the issue? Is it HK line issue or UK line issue?
While I have no experience with this particular issue, the following post seems like it might apply to your situation.
Bryanod wrote: (https://community.sling.com/message/10843#10843)
MTU might be something to look at. When you upgraded your connection your speed is slower than before because your sending more fragmented packets.
Go here and run the tweak test from the slingboxes location