We have a My Book Live and we have two wifi points. Our main wifi router (h2o) is in our house. This is what my wifes computer was hooked up to. We also have another wifi extender (h2o_ext) that my computer uses in our outside office. Her computer can access the My Book LIve just fine when she uses the (h2o) wifi and my computer can access My Book LIve just fine using the (h2o_ext) access. All good until we had to move her work station out to my office. She is now using the (h2o_ext) wifi access and cannot get into the My Book Live. Is there a setting under her computer that I need to change it to so she can access her files through (h2o_ext)?
Try setting a Static IP on the my book live and then try remapping it on the computer.