Super-Orders installation

[HMG]

I'm having a really tough time getting the newest release of Super Orders installed on Zen 1.3.7.1

I keep getting this error:

1062 Duplicate entry 'CA' for key 2
in:
[INSERT INTO zen_so_payment_types VALUES (NULL, 1, 'CA', 'Cash');]
If you were entering information, press the BACK button in your browser and re-check the information you had entered to be sure you left no blank fields.

Any suggestions as to a work around so I can continue with the installation?

Thanks in advance.

[HMG]

Any suggestions with this?

thanks!