Problem with keys

[Leo Treasure]

Hello,

I'm relatively new to GPG but I'm having this problem I need some advice on.

When I clear sign a message using a newly created key pair it always
chooses the sub key instead of the main key. This happens even when
using --default-key <the main key ID>.

In my settings, GPGPreferences I have the correct key in default key
selected. Also in ~/.gnupg/gpg.conf the default-key has the main key's ID.

I am running OS X Mountain Lion and the latest version of GPG
(GnuPG/MacGPG2) 2.0.19

I did not put an email address when creating the key is about the only
unusual thing I have done.

Any suggestions?