Yes. I had and have actually this problem, but with the 56k connection. I live in Italy, and i called Nintendo Italy Support...They were very unprofessional...They proffered me to send them Wii to change it...I was'nt agree, because i think it's a connection problem, not a Wii problem. So they told me to write an email to the support center. I had no answer.
I hope Nintendo releases a patch for the Wii Shop channel, i think it has a lot of bugs.