For best results, your LayoutDivs need to be wrapped inside the .gridContainer as it serves as the basic structure for your entire layout (mobile, tablet and desktop).
<div class="gridContainer clearfix">
Design View Screenshot
When you put Divs outside the .gridContainer, this can create rounding problems in many browsers because the inner div widths are all set in fractional percentages rather than whole numbers. Browsers don't fully understand how to render widths in fractions.
In the following example, I have the same set-up as shown in my screenshot above except my footer div is intentionally located outside the gridContainer. This allows my footer to be 100% page width.
If you understand and work within the limitations of FluidGridLayouts, they can save you a lot of time.
I looked at the URL you gave(in IE) and couldn't see this problem anymore. has that been resolved ?
This doesn't looks like a rounding problem to me as it will just shift a div marginally.
What's really annoying - undo/Ctrl-Z does not undo "visual" changes. I can edit text, resize a Div by dragging the right handle, do an Undo - and my text edit is changed - not the resize.
Yes this is a bit of PIA, the reason being some actions like, resize will have a CSS only impact while others like swaping the elements etc have both HTML and CSS updates.
and currently Undo will only work on the current file which is in focus (I.e HTML/source Code or CSS).
Hence, in nut shell, if you did a resize and then you are trying to do undo such that you focus is not on CSS file, it wont work.
to work around this , just switch to CSS code and then do undo and life is good again.