I had this problem with my roku too. I had to swap the micro sd card with the one in my cell phone. For whatever reason for me at least a different brand micro sd solved the problem. Hope this helps.
Why do you need the card at all? Take it out and leave it out.
If you have too many channels installed the overage will load as you need them and that's way better than having them all load all the time.
...having to do with The Channel Store issues?
I cant save game data without the card so it is new game every time I play...