Strange results from sys.partitions system view

There is a strange problem on some of new upgraded sql server 2012 servers,for example:

use testDB
go
select partition_id,object_id,index_id,partition_number,rows 
from sys.partitions 
where object_id = object_id ('testtable')
order by index_id 
select partition_id,object_id,index_id,partition_number,row_count
from sys.dm_db_partition_stats 
where object_id = object_id ('testtable')
order by index_id 
-- query results as below

partition_id         object_id   index_id    partition_number rows
-------------------- ----------- ----------- ---------------- --------------------
72057599707119616    158727718   1           1                3957149
72057599732875264    158727718   2           1                3957149
72057599738642432    158727718   2           1                3950892
72057599389859840    158727718   4           1                3957149
72057599714852864    158727718   11          1                3957149
72057599738707968    158727718   11          1                3950892
72057599736283136    158727718   11          1                3945037
72057599728025600    158727718   31          1                3957149
72057599678808064    158727718   48          1                3957149

partition_id         object_id   index_id    partition_number row_count
-------------------- ----------- ----------- ---------------- --------------------
72057599707119616    158727718   1           1                3957149
72057599732875264    158727718   2           1                3957149
72057599389859840    158727718   4           1                3957149
72057599714852864    158727718   11          1                3957149
72057599728025600    158727718   31          1                3957149
72057599678808064    158727718   48          1                3957149

Index 2 and index 11 index columns are:

indexid 22: Hotel(int), onlineDisplay(char(1)), CloseFlag(char(1))
indexid 11: onlineDisplay(char(1)), CloseFlag(char(1)), Room(int), Hotel(int), Currency(char(3)), PrepayReserveType(varchar(5))

So the question are:

1st: Why the two queries got different results?

2nd: Why the two indexes (indexid =2 and indexid=11) have multiple rows from sys.partitions

3rd: And the two indexes (indexid =2 and indexid=11) have different rows?

Many thanks.