[Koha] Problem with patrons holds

[Vitor Fernandes]

Hi there.

I've a serious problem... The patrons can exceed the number of holds allowed.
This is my circulation matrix.

Alunos CET 	                Monografia Geral 	3 	10 	0.50 	1 	0 	0 	2
	3 	0.000000
Alunos Doutoramento 	Monografia Geral 	6 	10 	0.50 	1 	0 	0 	2 	6 	0.000000
Alunos Erasmus 	        Monografia Geral 	3 	10 	0.50 	1 	0 	0 	2 	3 	0.000000
Alunos Erasmus 	    Monografia Referência 	3 	10 	0.50 	1 	0 	0 	2 	0 	0.000000
Alunos Licenciatura 	        Monografia Geral 	3 	10 	0.50 	1 	0 	0 	2
	3 	0.000000
Alunos Mestrado 	        Monografia Geral 	6 	10 	0.50 	1 	0 	0 	2 	6 	0.000000
Alunos Pós-graduação 	Monografia Geral 	6 	10 	0.50 	1 	0 	0 	2 	6 	0.000000
Docentes 	                        Monografia Geral 	6 	10 	0.50 	1 	0
	0 	2 	6 	0.000000
Docentes 	                    Monografia Handbook 	3 	2 	0.50 	1 	0 	0
	2 	0 	0.000000
Funcionários 	                Monografia Geral 	3 	10 	0.50 	1 	0 	0
	2 	3 	0.000000
Investigadores 	                Monografia Geral 	6 	10 	0.50 	1 	0 	0
	2 	6 	0.000000

For example the holds allowed for one patron with category "Alunos
Licenciatura" for item types "Monografia Geral" are 3 holds, but in
the OPAC the users can put on hold more than 3 items of that type.
Who I can solve it?
Which is the perl function, library for holding? Perl is not a problem
for me and maybe a can solve it changing the code.
Is a Koha bug?

Regards.
Vitor Fernandes