Rreadk problem

I'm trying to read an index with Rreadk, but I keep getting no bytes in
return. The record exists and the values looks ok to me in debug. Anybode
see what I'm missing?

typedef struct {
int key1;
int key2;
char key3[2];
} mykey;

mykey keyflds;
mykey *inkey;

//file opening etc, and then...
if ((fp=_Ropen("*LIBL/MYINDEX", "rr, riofb=N")) == NULL)
return -1;

keyflds.key1 = 1000;
keyflds.key2 = 233924;
memset(keyflds.key3, ' ', sizeof(keyflds.key3);
memcpy(keyflds.key3, "CA", 2);

inkey = &keyflds;

fb = _Rreadk(fp, &buf, sizeof(buf), __KEY_EQ, inkey, 10);

Best wishes,
Erik