[lazarus] Using SQL Object

[SteveG]

Could someone pls tell me whats wrong with the following code ?
I found it on a post on the fpc site (somebody else having this error 
about 2 yrs ago) and decided to use as my 'learner' - still has errors

I am using latest cvs of lazarus and rpm's of fpc from laz downloads
The test database exists and data is in FPdev - works ok from shell

procedure tform1.button1click(sender: tobject);
var
   Data : TMysqldataset;
begin
   Data:=TMysqlDataset.Create(nil);
   With Data do begin
     Host:='localhost';
     Database:='test';
     User:='root';
     PassWord := '******';
     SQL.text := 'select * from FPdev';
     Open;//Here an error "Internal error." occurs
     Close;
     Free;
   end;//with Data do
end;

suggestions much appreciated