Newbie library problem

Greetings,

I created a small .h and .c that define and implement a simple data structure, like this:
-->> queue.h
#ifndef QUEUE_H
#define QUEUE_H

#include "comunic.h" //required for type t_pedido
#define QUEUE_LENGTH 16

typedef struct queue {
        t_pedido requests[QUEUE_LENGTH];
        unsigned int currentLength;
} t_queue;

-->> queue.c
//I'll post only the headers of the functions:
void queueInit(t_queue *queue);
unsigned int queueGetLength(t_queue *queue);
int queueAddRequest(t_pedido *request, t_queue *queue);
t_pedido queueGetRequest(t_queue *queue);

I'm having trouble importing the defined type into other files. I declared a main() function in queue.c and tested the functions from there, all working out fine. However, if I create some other file like test.c with the exact same code and try to compile it (gcc test.c) I'll get a strange error:
-->> test.c
#include "queue.h"
#include "funcoes_serv.h" //for type t_pedido

int main(){
//the exact same code that was on queue.c's main() function
t_pedido aux = queueGetRequest(&myQueue); //gcc says "incompatible types in assignment"
}

However, the code is exactly the same and I never did get the "incompatible types in assignment" error when testing from queue.c. And the types are correct, as it's possible to see. What am I doing wrong?

Thanks in advance :)