Reset and Start Again for Auto Blog

Hi
I've being running Autoblog successfully for a couple of feeds for testing, now that I want to really use those feeds I'm not able to import anything.
I did delete everything from my post list and also from the trash. But I'm still not able to import.
I was thinking in deleting the content of the DB
Can an expert let me know witch rows should I empty and also if this is a good or bad idea...
Thanks