Problems with affiliate tracking link

I have a client running v7 Business and in the advanced documentation it indicates that this is possible however it doesn't work so any advice would be appreciated.

<img src="https://www.perfiliate.com/brains/process.php?PROGID=751&TYPE=sales&AMOUNT=NETQUOTEVAR:MYORDERTOTAL&TRANSID=NETQUOTEVAR:THEORDERNUMBER" height="2" width="1">


The actual output is as follows and the order amount is not being passed through so the link fails:

<img src="https://www.perfiliate.com/brains/process.php?PROGID=751&amp;TYPE=sales&amp;AMOUNT=NETQUOTEVAR:MYORDERTOTAL&amp;TRANSID=SD11EH10000033" height="2" width="1">

[Duncan Rounding]

Have you tried using ACTINICORDERTOTAL instead OF MYORDERTOTAL?
I think that MYORDERTOTAL refers to one of the formatted totals listed below in the guide.