I had same problem but resolved.
First make sure the document is publishable and subscribe on both the brokers of the territory.
If it is not working it may be because the definition of the document varies on two brokers i.e. version. So you can delete/re-import the document into both brokers and try sharing the document.
I had to go through the both the steps above.
Regards
Rama Gowda
#Universal-Messaging-Broker#broker#webMethods#Integration-Server-and-ESB