If none of your orders are legitimate, then do the following.
NOTE: **BOTH** steps are required:
1. Use your admin area to delete all orders. Yes, that means clicking on each one, one-by-one, and clicking the Delete button.
2. After they're ALL deleted via the admin, run this command in Admin->Tools->Install SQL Patch:
Code:
truncate table orders;
**** NOTE: DO NOT DO STEP #2 UNTIL YOU HAVE DONE STEP #1 FIRST ****
After that, your next order should start at 1 again.
Test 2 or 3 orders, and make sure the numbers count up correctly.