I installed Bagnon 7.0.3 and deleted all old config files (bagnon.* and bagbrother.*) from WTF... I log into the realm "EU: Die Silberne Hand" and everything works. I have some chars and BagBrother allows me to view the bags and banks of the other chars. After switching to the connected real "EU: Die ewige Wacht" BagBrother stops working. It's not possible to select other chars from the Bagon-(bag-)window and the tooltip does not show any infos. When I quit WoW and delete the info for the second realm from BagBrother.lua everything works again (for the chars on the first realm).
BagBrother_example.zip

Thanks for the addon, I hope this will get fixed in the near future.
Takamoko

I also am having this issue... basically I need to not use BagBrother on other realms until it's fixed... :(

Fixed in dev version