Product URL returns 404 after import

[bonsaiko]

Hello,

 

I'm making some import tests because I have a huge database from another e-commerce site (not prestashop) so I have to create the perfect csv files that will import all the products and their features. 

Anyway

 

When I import a product, then I go to its URL to check if it worked fine. 

Then I create another csv file, containing another product, and so on...

 

But I noticed that the URLs of my former products are no longer ok... When I click on the older products, I'm getting 404 error pages. 

Could you please help me ?

 

Thanks