noobie question. percussion instruments

[Roberto Morales]

Dear list

I am new in Lilypond and got the following problem defining my percussion 
instruments. According to the  manual I did the following

this example works fine

\version "2.12.3"

#(define mibataca '(
(acousticbassdrum diamond #f -4)
(hiwoodblock  default #f 1)
(lowoodblock default #f 3)
(acousticsnare cross  #f 2)
(lowfloortom default #f -2)
(highfloortom default #f -1)
(lowtom default #f 0)
(opentriangle triangle #f 5)
        )
)

timb = \drummode {bda8 sna wbh wbl tomfl tomh trio }

\score {

\new DrumStaff  {
\override Staff.StaffSymbol #'line-positions = #'(-2 1 )
\override StaffSymbol #'line-count = #2
\override Staff.BarLine #'bar-size = #3
\set DrumStaff.drumStyleTable = #(alist->hash-table mibataca)

\timb
}


but, when add cymbals to the same instrument they never got their new positon 
or noteheads.

I define a cymbal drums and same thing happens. Is this a bug or cymbals have 
some parameters extra i missing ?


#(define platillos '(
(chinesecymbal triangle #f -3 )
(
crashcymbala  diamond #f 0)
        )
)

pla  = \drummode {cymch cymc}

\new DrumStaff  {
\override Staff.StaffSymbol #'line-positions = #'(-2 1 )
\override StaffSymbol #'line-count = #2
\override Staff.BarLine #'bar-size = #3
\set DrumStaff.drumStyleTable = #(alist->hash-table platillos)

\pla
}
%-------------------------------

thanks in advance


roberto