Can not get required info from 'caller' at 'DB::sub'

[KES]

http://paste.scsys.co.uk/502483

 Also it is strange to see the DB::DB is called twice for t3.pl (Notice the 
line 82, 85 at the paste)
The twice call does not occour if I remove 'caller' from t3.pl:4. Like: print 
'FROM:';

The output:
...
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
t3.pl:9         my $x =  3;

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
t3.pl:11        t();
SUB: main::t - 
FROM: main - t3.pl - 17

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
t3.pl:4         print "FROM";
FROM
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
t3.pl:13        $x++;
3
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
t3.pl:18    print $x;