Sales Report not functioning

Hello,
i'm using OC 1.5.1.3, after some products sold (invoice generated) , when i click Report --> Sales --> Order --> No Result! no matter i choose date to by day on all statuses.

Products Viewed Report work fine.
Customer Orders Report No.

Can i know how it works?
Many thanks

i've install a 1.5.1.3 version to test out too, i found same problem with you, no sales or order report generated, wondering if anyone face the same, or this might be a bug?? i'm looking forward on your post reply oc5. hope to get some answer or guide.

Hmm...based on what I have, it works only when payment is done, not free products. Real cash payment completed, then it is shown on the report. I'm not 100% sure if im right though.