I can't receive Mario Kart channel updates anymore

Hey guys, could someone please help me... Two weeks ago I searched the internet for a mario kart wii save so I could unlock all the players. I didn't know that installing one of those saves wouldn't allow me to play online anymore. Luckly I had backed up my save using Savegame Extractor so I just installed it back using Savegame Installer. I checked if everything was allright and was able to play online flawlessly, so it was a big relief. But I noticed that every time I went into Mario Kart channel and clicked on "Receive Mario Kart channel updates", I got the same error message. It's the following: "There is a problem with the Wii system memory, so WiiConnect24 cannot be used. Error code: 107216". I already checked support.nintendo.com and they say that this error code is not a specific error code - and they show me a screen for general troubleshooting, telling me to see if my router is working OK and etc, but I know it's ok because I can play every other game online with no problems, I can even play mario kart online at Nintendo WiFi.
Today, the new tournament begins (the one in the mall course) but because I can't receive updates, I'm stuck at the previous tournament...... please, doesn't anyone know a way to fix this?
I think it's important to say that when I read that the problem was with the "wii system memory", I tried to solve it by deleting some channels to free some space... but got no luck.
Thanks for your help....

 

Is there no other way?? I have many things stored in my wii and would be very complicated to back them up and reinstall them...

 

But the problem is that I don't want to lose everything I have!!
And this has been happening for 2 weeks now, so I doubt it's a server problem...

 

Thank you so much!!!!