In Lion and Mountain Lion Apple (due to licensing restriction) used its own implementation of Samba protocol that is incompatible wit PBO Core. For that reason, network shares on Macs with new OS are not accessible to PBO Core.

Solution!

Step 1:
- Turn OFF "Share Files and files using SMB (Windows)" in System Preferences -> Sharing ->File Sharing ->Options
- Install SMBup http://eduo.info/apps/smbup
- Run...
- Select "add new shared drive" and select folder you want to share (leave guest account on)
- in menu File select Save all
- in menu Actions select Start Samba

Voila!