what files are involved with calculating the order totals

Hi there

The title says it all really. I'm having an issue where the shipping estimator is coming up with a different price for shipping than what appears further in the checkout process and I want to try to figure out what might be going wrong.

Which files would I need to have a look at?

thanks :)

I believe it is /includes/classes/orders.php

I'm having an issue where the shipping estimator is coming up with a different price for shipping than what appears further
Who's estimator are you using?
What shipping methods do you have enabled?

kobra:

Who's estimator are you using?
What shipping methods do you have enabled?

My shipping options come from the Big Royal Mail addon. All the usual suspects out of that mod. I think it may also have included a few changes to the shipping estimator in it. I take it it's got something to do with that then.

Probably so and why I asked which one
May be another that uses Big Royal Mail might chime in with their experience