I've successfully cloned table shipping modules in the past but now I'm running into a problem and I'm not sure of the cause or the solution.

When I try to install the newly cloned module, I get this error:
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1062 Duplicate entry 'MODULE_SHIPPING_TABLE_COST' for key 2
in:
[insert into configuration (configuration_title, configuration_key, configuration_value, configuration_description, configuration_group_id, sort_order, set_function, date_added) values ('Shipping Table', 'MODULE_SHIPPING_TABLE_COST', '25:8.50,50:5.50,10000:0.00', 'The shipping cost is based on the total cost or weight of items or count of the items. Example: 25:8.50,50:5.50,etc.. Up to 25 charge 8.50, from there to 50 charge 5.50, etc
You can end the last amount as 10000:7% to charge 7% of the Order Total', '6', '0', 'zen_cfg_textarea(', now())]
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.
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Any clues? When I hit the back button the new module seems to be partially installed. It shows the Remove button and the edit button but the rest of the information seems missing. If I hit Edit, there are just a bunch of blank fields with no labels or anything. I've tried removing and reinstalling but get the same results.

Of course my client needs the new shipping rates right away, which is probably why I'm having trouble