Errors with fraction quantities

Hi, I have a plug-in that allows for fraction of an item. For example, a user can purchase 1.75 of an item. Most items are in steps of .25, so 1, 1.25, 1.5, 1.75.

If I select anything other than a whole number, I get 2 errors:

An error (11812) occurred while processing your PayPal payment. Please contact the store owner for assistance.
An error (10413) occurred while processing your PayPal payment. Please contact the store owner for assistance.

I see that error 10413 is related to cart quantities.

“10413 Transaction refused because of an invalid argument. See additional error messages for details.

The totals of the cart item amounts do not match order amounts. If you receive this error, be sure the total of the payment detail item parameters, such as ItemTotal, HandlingTotal, TaxTotal, and so forth add up to the order total.”

Are there issues with this and fraction of a item?

Thanks!