Query not working on some tables

Heyas,

The following query:

SELECT

IOS.INDEX_ID,
O.NAME AS OBJECT_NAME,
I.NAME AS INDEX_NAME,
IOS.LEAF_ALLOCATION_COUNT AS PAGE_SPLIT_FOR_INDEX,
IOS.NONLEAF_ALLOCATION_COUNT PAGE_ALLOCATION_CAUSED_BY_PAGESPLIT
FROM SYS.DM_DB_INDEX_OPERATIONAL_STATS(DB_ID(N'DB_NAME'),NULL,NULL,NULL) IOS
JOIN
SYS.INDEXES I
ON
IOS.INDEX_ID=I.INDEX_ID
AND IOS.OBJECT_ID = I.OBJECT_ID
JOIN
SYS.OBJECTS O
ON
IOS.OBJECT_ID=O.OBJECT_ID
WHERE O.TYPE_DESC='USER_TABLE'

Source:

http://social.technet.microsoft.com/wiki/contents/articles/25473.sql-server-dmv-to-track-page-split.aspx

Doesn't always work the error message I get is:

Msg 102, Level 15, State 1, Line 8
Incorrect syntax near '('.

Any help is always welcome.

Thank you.