Hello edecoy -
We are not aware of any large scale issues posting listings to eBay over the weekend, so it is unclear what may have occurred for you. If there was an API error from eBay when you attempted to post, you can see the resulting notification by clicking on the red notifications box in the upper right of your account pages. If eBay's system found an issue with your listings, the reason will show as an API error.
If you are unable to locate any errors or are unsure how to resolve them, please file a support case from under the Help tab of the site letting us know the titles of the affected listings and we'll be happy to look into it for you.