TSQL CONTAINSTABLE ISABOUT() makes an incorrect match

Question

I'm using SQL Server 2008 R2, and using CONTAINSTABLE ISABOUT() to identify key phrases in document titles. However, one specific key phrase is yielding false positives. They keyphrase is: "p-h-c industry" (without the quotes). Here's some sample code that illustrates the problem:-

CREATE TABLE tmp_test (myidentifier nvarchar(30) NOT NULL, mytext varchar(max));  
CREATE UNIQUE CLUSTERED INDEX test_key ON tmp_test(myidentifier);  
CREATE FULLTEXT CATALOG tmp_test_cat;  
CREATE FULLTEXT INDEX ON tmp_test(mytext) KEY INDEX test_key ON tmp_test_cat;  
GO   

INSERT tmp_test VALUES ('good case','Western p-h-c industry');
INSERT tmp_test VALUES ('bad case','competitive advertising industry');
GO  

SELECT * FROM CONTAINSTABLE (tmp_test, mytext, 'ISABOUT ("p-h-c industry" WEIGHT (.8))') ORDER BY RANK DESC;  
go

KEY                            RANK
------------------------------ -----------
Informational: The full-text search condition contained noise word(s).
good case                      15
bad case                       15

(2 row(s) affected)

I would expect the SELECT * FROM CONTAINSTABLE() to only return a row for the 'good case' since there is in an exact match. But it's also returning a row for the 'bad case' even though the keyphase "p-h-c industry" does not appear in the bad case text.

Can anyone suggest a fix or workaround? I have to do it using CONTAINSTABLE() since the code architecture is built around that. Thanks