command og_groups: [gid] not working

when i use the command
og_groups: [gid]
the node which is created lacks the proper gid in the node_access table
if i say og_groups: [12] it still enters 0 for gid.
if i remove og_groups: [12] the node becomes public and has og_all rather than og_subscriber as the realm so atleast that is working.. but why the 0 for gid????