oneworld - Backtracking on BA award flights

I'm trying to book award flights using my BA miles. I would like to have the following itinerary:
LHR-YYZ-LGA-DCA-MCO-MIA-LHR

The legs from LHR to the US/Can and back are BA, and all the internal flights are AA, so that they can be included in the award ticket.

The BA agent tried to book the itinerary for me, but couldn't manage the DCA-MCO leg - she said it was backtracking. :(

What exactly does that mean, and how can I tell whether an itinerary includes backtracking or not? Is there any on-line tool that can help?
Also, can anyone suggest an itinerary from London that includes Niagara Falls, New York (any airport), Washington (any airport) and Orlando, and does not backtrack?

You would be better off to ask on the BA forum about the intricacies of BA award rules. Backtracking means a change in the direction of motion (from east to west, for example). BA imposes these rules to prevent having too many stopovers on a ticket, and some routings are impossible. Your options are to redeem a Oneworld award on BA (different rules), or to redeem on a different FF plan (not BAEC). You'd have to meet the rule requirements. I suspect there is no way to fit in the DCA stopover within the BA rules for the award that you are using.

I'm trying to book award flights using my BA miles. I would like to have the following itinerary:
LHR-YYZ-LGA-DCA-MCO-MIA-LHR

The legs from LHR to the US/Can and back are BA, and all the internal flights are AA, so that they can be included in the award ticket.

The BA agent tried to book the itinerary for me, but couldn't manage the DCA-MCO leg - she said it was backtracking. :(

What exactly does that mean, and how can I tell whether an itinerary includes backtracking or not? Is there any on-line tool that can help?
Also, can anyone suggest an itinerary from London that includes Niagara Falls, New York (any airport), Washington (any airport) and Orlando, and does not backtrack?Maybe because AA has no DCA (or IAD, BWI) to MCO service, and you would have to go DCA-MIA-MCO or DCA-LGA-MCO? But not knowing how the BA partner awards work, I have no idea, and you are definitely better off asking the BA board.

Thanks a lot - I will repost on the BA forum. I originally put it here because I wasn't sure if it was a BA or AA issue.