Resizing groups of objects disturbs their spacial alignment

In my few days of playing with Balsamiq, I've run into the following issue several times...

Example scenario...

I create window, add a tree widget to its left edge, add V and H scrollbars to the tree, and then start to add other elements to the window. Ultimately, I realize that I need to make the main window larger to accommodate my final UI.

Obviously, I can enlarge the window, then selectively move / resize the tree and scrollbars so they are visually correct in the new window size. Unfortunately that's gets tedious as the window contents get more complex.

I've recently discovered a much simpler way to accomplish this, which involves:

- Select the items in question (in my example, the window, tree, V and H scrollbars
- Resize the entire group together by dragging the resize handles

This method basically does the right thing, except if the delta change in overall size is very large, the alignment of the objects start to get wonky. That is, all of the objects start to "drift" from their intended positions. The larger the resize amount, the worse the drift gets. Ultimately, that means each object that was part of the resize selection set needs to be individually tweaked again, making this method no better than the earlier method of handling each object individually to begin with.

As a programmer myself, this issue would seem to indicate some sort of floating point or rounding error in the object resize routines.

Would it be possible to improve the resize feature so that when a group of objects is resized, their spacial relationships are better retained?

Thanks,

Jeff Godfrey