Here is what I would do if my shipping stats were low:
1) Add a section on the first page noting that Standard Flat Rate Shipping is from Canada; shipments may be delayed by customs as well as the extra distance. Most of the things I've received from Canada take about 2 weeks. This is beyond eBay's standard time estimates. (Can you use your feedback dates to estimate how much your shipping time varies from eBay's?)
2) Send an email when I ship noting that I shipped it that day, but it is traveling from Canada and may be delayed by customs and distance. If shipment tracking (if used) shows that the shipment seems to be delayed in transit, send another email stating that fact and an apology for your inability to affect customs/distance.
3) If payment isn't cleared on the day it is paid, add something to your first page letting people know about the delay. Way back when you could take checks, I had a sentence about my tiny bank taking 30 days to clear a check. That way the customer could decide up front if that would be a problem. An unexplained payment clearance delay could be confused with a shipping delay.
Hope these ideas help. Good luck!
-- Barbara
