Hello, Is there a certain time for a new site to start indexed for page rank check? although the site has a lot of back-links ...!!!
It's because your site was created after the last pr update. Within the next update you will be able to see the actual pagerank of your site.
It's not fix for new or old site, any site can lost pr and new site can award any pr if your site have quality back links then, otherwise try lifetime, site will not award pr, don't wait, start to build good links today and see better tomorrow