Nesting beyond 5 level on left hand side pane of HTML report.. docbook 1.74.3

Hi,

 

I am using docbook version 1.74.3 and trying to generate HTML report using it.

 

I have lefthand side navigation pane on the report and I am only able to go 5 level deep when I expand ('+' sign) or collaps ('-' sing) it. I am not able to get ('+' or '-') sign if I have headers section that are more than 5 levels deep. It only shows bullets instead of ('+' or '-') signs for all the headers thoes are 5 level deep.

 

Is this the limitation or there is any parameter I can set to achieve this?

 

Thanks in advance.

 

Bela.