Mac OS 10.6 automatically sets permissions when a drive is formatted HFS+ (non journaled) that may make writing to the drive over SMB not function properly. To fix this the permissions must be changed on the drive.
1. Connect the drive via USB to your Mac OS 10.6 computer.
2. Select the drive on the desktop and press Command+I.
3. Click on the Sharing & Permissions tab to expand it if needed.
4. Select Everyone and change the permissions from Read Only to Read & Write.
5. Once complete permissions should appear as below:
6. Disconnect the drive from USB and connect via SMB. The drive should now have read and write permissions on SMB.