I have the dimming netflix problem, but I think its ridiculous to have to spend another $25 on cables. My Wii is brand new, just bought it at Xmas, and its ridiculous that the cables are garbage.
another thing I dont like about the Wii and netflix is that you can not access the movies like you can online. In fact, ive found that some movies you can find on instant view online, you cant find searching on the Wii. But if you put them in your queue online, then they will show up on my wii.
Ive also encountered a slow down just weeks after using the Wii, but my PC still work well .
I have had this dimming problem for a couple of months. Drives my wife crazy because she is Netflix movie junkie and is always asking me to fix this darkness problem. I finally fixed it!! It had nothing to do with the wii or the cables. Hopefully this is your problem too, because it is such an easy fix.
It was all in the TV settings. I am using a wii2HDMI adapter (Google it) and it lets you connect your wii to your TV through an HDMI cable. Well somehow the TV settings for the HDMI2 input on the TV got changed to Energy Saving mode, which automatically dims the TV every time HDMI2 was selected. I have an LG LED 47" TV and you simply go into the input selection screen on the TV, select the HDMI2 input (in my particular case) and then click the settings button. You will see all sorts of settings like contrast, brightness, color, etc. On that screen it also has a setting for Energy Saving and mine was set to ON. So I simply turned it off and the brightness was back!! I realize you may have a different TV and different cabling connection, but it may still be that your TV got switched to Energy saving mode somehow.
Hope that works. I have never seen a solution like mine, but I bet all a lot of people googling this problem will find that this fixes their problem. Hopefully! Good luck everyone.