Thank you for your reply to my query.
You appear to be right in your second possibility. After checking the LindEx section of my Dashboard I found that I had a valid payment method and had placed a "Best Rate" or
Limit Buy" (can't remember which) but, I do remember thinking that I was buying $L at a cheaper rate. I don't understand anything about LindEx or exchange rates.
I'm going to attempt canceling the open order and then hopefully I can have it placed in my $USD Balance as I originally intended.
Thanks again for your help.