Move/Translate GroupItem w/ masks and effects?

Question

All,
I have a document with a single layer and a single group (GroupItem) in that layer.
Unfortunately, I didn't create the .ai file, so I don't know exactly what is in the group; however, there appears to be a bunch of complex clipping masks and gradient effects, etc. deeply nested within it.
I've successfully scripted a few tasks like resizing the group with no ill effect... in other words, this works as expected:
app.activeDocument.activeLayer.pathItems[0].resize(50,50);
However, as soon as I try to move/translate/reposition the group, all the effects/masks seem to go wonky, I've tried all of the below with no success (200 is just arbitrary as a test):
app.activeDocument.activeLayer.pathItems[0].left = 200;
app.activeDocument.activeLayer.pathItems[0].translate(200,0);
I have no problem moving the group around on the document with my mouse... all the effects/masks are still nice and clean, so I'm confused as to why I can't do the same thing via JavaScript.

Answer 1

For folks who're interested...
I ended up taking an entirely different approach:
Instead of moving the logo group, I decided to leave it alone, and move the artboard instead.
This solution obviously only works for my scenario, and artboards are a pain in the @$$! to work with via JavaScript:
app.activeDocument.activeLayer.pageItems[0].resize(50,50);
app.activeDocument.artboards[0].artboardRect = [left, top, right, bottom];
Anyway, I'd still be interested in if anyone knows for sure that there's a known issue with trying to move artwork via JavaScript when there's clipping masks or effects involved.