I encountered this a few years ago. I believe that clearing the history/website data helps and then follow that up with a "reset" of the iPad - quote below.
If you search for the issue on the web, there are several results posted.
Next, reset the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider if it appears on the screen - let go of the buttons. Let the iPad start up.