relative number fields

[Annegret Weng <weng@exp-math.uni-essen.de>]

I am using the Pari-Library and I would like to create a relative number
field by using the function rnfinitalg. But I always get a run time error.
 
First I created a number field nf with the function nfinit0 and with a
polynomial in # (say for example #^2+5). Then I created an object of type
polmod (e.g. 3*#+2). Finally I called rnfinitalg with the parameters nf,
a polynomial in x having as a coefficients objects of type polmod and
prec=3. At the end I got the error message "type mod I forbidden in gmod".
What did I do wrong?

Annegret