Trade Depots not exporting/importing

[elZaphod]

I had started getting all sort of trade backup problems including one depot sitting full and also being unable to import oil so my plants were shutting down if my pumps couldn't keep up. I tried monkeying with the import/export, turning on/off local deliveries, demolishing and recreating trucks, etc. Then I decided to set it to cheetah speed and watch a three hour movie in the next room. When I came back things had improved and my exports were moving again. Don't ask me why.