After several hours of testing i finally figured out why my page is acting strange.
The page i'm working on is the root site page and when visiting the page as:
everything works fine. (ie i have tabs with grids in tabs and a tab a submit form). Paging, sorting, ajax - everything works (except for export but i can live with that)
however when visiting the exact same page as
nothing works (paging, sorting, tabs, submit form doesnt work). This took forever to figure out bc almost everyone access the page as http://mypage.net. it took some time before i realized that everything work correctly when the URL is http://mypage.net/index.aspx
Problem is, I still dont know how to fix this. I guess i could use a blank page with a redirector to index.aspx. This seems lame. I tried a URL mapping in the web.config file but that didnt do anything.