I've been looking at the OU Blog module and seem to have a problem - I've described the steps I took to produce this below

1. Clean install of Moodle 1.9.4
2. Install OU BLog module - appears in moodle/mod/oublog
3. Activate module through admin->notifications. Tables listed as installing correctly
4. Leave Blog User Pics set to default.
5. Two users added: test1, test2
6. Test Course created with default settings and name of 'Test Course'
7. OU BLog added as activity with default settings
8. user1 enrolled on course
9. Blog Tag block added to course
10. Logout admin user
11. Login as user2
12. Post personal blog via profile with tag of 'user2'
13. Logout
14. Login as user1
15. Access test course
16. Blog Tag block shows tag 'user2'

Can provide access to clean environment if replication needed.