Not sure if you will find this helpful, but only rarely do we have currencies other than CAD.  I should also note that I have a USD bank account but we report in CAD. 

This is how I handle it:

For example, for a sale to the US, I enter the sales invoice amount in USD (CR to Sales), then add a second line on the invoice with the exchange amount on that day (also CR to Sales).  A third line on the invoice is a negative of the same amount on line two (DR Exchange Expense).  This will give you an invoice to provide to the company in USD (of $38,000.00 in my example below), and will provide an approximate sales value in CAD for your internal reporting.  The Receipts journal entry will look like this:
     DR - AR     $38,000.00
     DR - Exchange Expense     $13,000.00
     CR - Sales     $51,000.00 (this will be a combination of Lines one and two, the actual value of the sale in CAD)

On the day of the receipt of funds, I calculate the actual exchange on that date and make the correction to the sales invoice by adjusting the original sales entry to read:
     DR - AR     $38,000.00
     DR - Exchange Expense     $12,851.20
     CR - Sales     $50,851.20

Then I can post the actual USD payment received, which will look like this:
     DR - USD Bank     $38,000.00
     CR - AR     $38,000.00

Not sure if you will find this helpful, but only rarely do we have currencies other than CAD.  I should also note that I have a USD bank account but we report in CAD. 

This is how I handle it:

For example, for a sale to the US, I enter the sales invoice amount in USD (CR to Sales), then add a second line on the invoice with the exchange amount on that day (also CR to Sales).  A third line on the invoice is a negative of the same amount on line two (DR Exchange Expense).  This will give you an invoice to provide to the company in USD (of $38,000.00 in my example below), and will provide an approximate sales value in CAD for your internal reporting.  The Receipts journal entry will look like this:
     DR - AR     $38,000.00
     DR - Exchange Expense     $13,000.00
     CR - Sales     $51,000.00 (this will be a combination of Lines one and two, the actual value of the sale in CAD)

On the day of the receipt of funds, I calculate the actual exchange on that date and make the correction to the sales invoice by adjusting the original sales entry to read:
     DR - AR     $38,000.00
     DR - Exchange Expense     $12,851.20
     CR - Sales     $50,851.20

Then I can post the actual USD payment received, which will look like this:
     DR - USD Bank     $38,000.00
     CR - AR     $38,000.00

Thank you for your input.  I called Sage and this issue is actually something that cannot be corrected.  I can send my files into Sage and they will fix the issue.