Problem with generated code

Hi,

I am using javacc for a seminar at the university. The generated parser 
  is supposed to parse a simplified java-near language. So after coding 
the jj-file it generates the parser error-free, but when I try to 
compile the generated code with javac I get 90(!) "cannot resolve 
symbol"-errors.
For example:

p4.java:304: cannot resolve symbol
symbol  : class SimpleCharStream
location: class p4_p.p4
     jj_input_stream = new SimpleCharStream(stream, 1, 1);
                           ^

I searched the web for this message and found that a 
package-naming-error may be the problem, but in every file the package 
is set properly, so that is not the problem.
Thanks in advance for help.

Regards
Christian