.uno:GoDown, when used with Sel true, only selects two cells when using By or Count greater than 2.

Other problems:
"Select" does not select anything at all. Only "Sel".

Using Sel false correctly moves down the specified number of cells.

Here is a Sub to ilustrate this beaviour:

sub xxx
rem ----------------------------------------------------------------------
rem define variables
dim document   as object
dim dispatcher as object
rem ----------------------------------------------------------------------
rem get access to the document
document   = ThisComponent.CurrentController.Frame
dispatcher = createUnoService("com.sun.star.frame.DispatchHelper")

rem ----------------------------------------------------------------------
dim args1(0) as new com.sun.star.beans.PropertyValue
args1(0).Name = "Sel"
args1(0).Value = false

dispatcher.executeDispatch(document, ".uno:GoToStart", "", 0, args1())

rem ----------------------------------------------------------------------
dim args2(1) as new com.sun.star.beans.PropertyValue
args2(0).Name = "By"
args2(0).Value = 9
args2(1).Name = "Sel"
args2(1).Value = true

dispatcher.executeDispatch(document, ".uno:GoDown", "", 0, args2())

rem *** At this point only two cells are selected instead of 10! ***

rem ----------------------------------------------------------------------
dispatcher.executeDispatch(document, ".uno:Copy", "", 0, Array())

rem ----------------------------------------------------------------------
dim args4(1) as new com.sun.star.beans.PropertyValue
args4(0).Name = "By"
args4(0).Value = 1
args4(1).Name = "Sel"
args4(1).Value = false

dispatcher.executeDispatch(document, ".uno:GoRight", "", 0, args4())

rem ----------------------------------------------------------------------
dispatcher.executeDispatch(document, ".uno:Paste", "", 0, Array())


end sub