Payment method report not showing the correct amounts

Hello,

I have looked around google and the issue queue but I cannot find my problem anywhere so I write it down here:

I have commerce module installed 7.x-1.4, and Commerce reporting version 7.x-3.0-beta2.
I have two payment methods enabled: paypal wps and Sermepa (some spanish banks) and for all the development I was using for a month or so the example payment method doing some example purchases.
Now the store is up and working for a couple of weeks or so.

The problem comes with the payment method report in which I have two problems:
1. Although I already disabled and uninstalled the Example payment method module the amounts paid with the example method still appear in the table, even though I already deleted the orders.
2. In the sales report, which includes all the orders that have the completed & pending states, the total amount of sales is 37 euros less, and two orders less than the amounts shown in the payment method report.

For what I have read around, I guess it has something to do with a difference between completed payments and transactions that I don't arrive to understand.

Can anyone give me some light on this?

Thanks!