Delphi and the activex componant (again)

After thinking I had a degree of sucess actually getting it to compile and run, im still stuck with it.

procedure TForm1.BitBtn3Click(Sender: TObject);
begin

devname := 'tvthing' ;

devfile := 'p:\sonytv.cde' ;

devID := 0 ;

slinkenum := 1 ;

//send to all 8 IR ports

portnum := $FF0 ;

result:=Slinkx1.AddDevice(devname, devfile, devID, slinkenum, portnum);
end;

Returns -1 in result - to me this means a failure (There is no mention of result codes in the help) - any ideas why this is failing?? I got it to compile and run Ok by cutting and pasting parts of the delphi 3 generated import\SLINKXLib_TLB.pas file with the delphi 4 generated one that I was emailed a little while ago. It seems to be falling over on the addition of the device so sending stuff is not possable.