If you are sure that the columns are properly configured then there might be an issue with the values that are going into them. The best way to help debug what is wrong with the query is to get the full query text and check it for problems, then we can make any updates that are needed in the store order summary server behavior.
To get the full text of the query you should add in this line of code just after what is currently on lines 460 and 470, add a new line after the one that starts with "$WA_Sql = " and put this code on it:
die($WA_Sql);
After you add in this code run a test and it should print out the query that is used. If you can't identify any issues with it post back with what you get and we will check it out.
For the currency code you should check lines 238-239
$PP_DirectPayment_required[0][$nextIndex] = "Currency";
$PP_DirectPayment_required[1][$nextIndex] = "USD";
You need to update the USD to GBP.