why it is not rendering the datatable properly
In what way is it not rendering properly? What is happening that is different from what you expect? You still haven't said what the problem is.
I don't think you need the "reRender" attribute on your datascroller, I think that is implied by the datacroller being in the datatable's facet (I have no "reRender" on mine and it works fine, nor is there one on the RichFaces example when using facets - did you look at that?).
I also see you have filters and sorts toyour columns. That might be confusing matters. Remove everything that you don't need and see if the datascroller starts working, at the very least this will let you work on the datascroller issue in isolation.
This is how I have my datascroller set up and it works.
Ellipses ("...") are just places where I have delete sections of my JSF, I just want to show you the structure I used as the page is doing some quite complex data management.
I lifted it all (pretty much) from the examples.