Hi John, and thanks
var textblock = app.activeDocument.textFrames.itemByID(3771);
textblock .move( [0, 4] );
but still doesn't move the textframe.
Didn't think it was relevant, but here you go (an instance of "textFrame.id", from InDesignCS5_ScriptingGuide_JS.pdf)
The id was wrong, just like you said.
This line now works:
app.activeDocument.textFrames.itemByID(3768).move( [0, 4] );