hi,
Have you found a solution to this problem? I also have a macbook that constantly disconnects from my time capsule wifi. At first, I thought it was my macbook but now I'm on another wireless at home that goes through our Comcast wifi modem and it's fine. We also have another macbook, a pc based laptop, 2 iPhones and 2 iPads which all connect to time capsule no problem. And I also have the same issue w/the guest network. I went to the genius bar to get free advice and they could really not offer anything being that my time capsule is at home. I also have one wifi extender (airport express).