1.4.9.1 - Paypal Standard Shipping not passing?

I am having a problem with OpenCart 1.4.9.1. I have the site up and running using paypal standard module with PDT token running correctly. Orders are coming in and I am happy with the functuality of the cart although there is one problem I am having. I have set the flat rate shipping module as the only shipping method, although when the total is sent off to paypal it is minus the flat rate shipping fee.

How can I get opencart to tell paypal the shipping fee?

I get an email with each order stating the following:

PP_Standard - Possible Scam: IPN/PDT Price "52.86" does not match OpenCart Total "55.8533". Order needs manual verification

DEBUG GET VARS::route=payment/pp_standard/pdt
tx=?????? ** ive blanked this out for security purposes!!! **
st=Completed
amt=52.86
cc=GBP
cm=lpY=
item_number=


I hope you can enlighten me on this problem I am having.

Thanks

If your shipping is not being passed, it typically means that your paypal account shipping preferences aren't set correctly.
See here for information about that:
http://www.opencart.com/index.php?route ... h=32_35_60