So we're clear, the solution in this thread did not work for me.

Here's my situation: I had a Dell Inspiron 5150 running 10.10 connected to a 500GB WD external USB drive. I never had to muck with smb.conf or fstab, and I could share the drive over my network to other computers running OS X with out any problems. Recently, I acquired another computer which now runs 10.10. The drive mounts just fine on this computer. When I attempt to share it, I can see it on the two other computers on my network, one running Ubuntu and the other OS X. However, I can't access it. Kind of a bummer.

A little help, please?