Update your burner's firmware (remove any disc and close the tray before updating then reboot after it's finished) and try burning at 8x or 12x.
Are you going to play that disc on a DivX player? If not you might want to use only the UDF 1.02 filesystem, so that you can keep the original filenames.
sorry didn't worked T_T
I guess I'll be dismantling this and do a manual cleaning of the lens for a last try before relegating this as a reader only T_T