this happen in official sample
http://dev.sencha.com/deploy/ext-4.0...um-search.html

and the page counter continues to increase !!!

folow steps:
1 - try to search "form" and click next page (pagingtoolbar)
2- now change your search to "grid"
3 - you still in page 2 and when second search with no results happen, listview dont appear!

sorry for my english