Does it work OK when you use the same browser software on a desktop or laptop PC or Mac? If so, then I would try reinstalling the browser software on the iPad. As I understand, Slingplayer works with Internet Explorer or Firefox on PC and Mac computers, but not with chrome or safari. I have neither a Mac or an iPad, however, so can not personally vouch for what (if any?) web browser plug in will work for SB on an iPad web browser.
I have read in several places that there is a mobile Slingplayer app for sale that works well with the iPad.