---- update 5/9/17, see my reply below for a fix ----

Hi all,

I recently noticed my cell background images not playing nice in Outlook desktop. Basically my email was 600px wide, but when i printscreen the edm test from my inbox it measured 750px in photoshop - which was usually fine as all the elements scaled up and fitted nicely. Except when i first used a background image in a fixed width table cell (via the widely used backgrounds.cm method) - it did not scaled up like a inline image. I should note that Litmus test's were showing up fine for the email test on all clients and devices, but it was my own personal inbox test that was not rendering correctly.

Here's a obfuscated view of what it looked like
Here's a obfuscated view of what it looked like

After much testing and internet searching i came up empty handed until i decided to check my laptop's display settings and noticed the Scale and Layout was set to 125% (which makes sense as to why the email width was 750px wide instead of 600px). After changing to 100% and restarting i then noticed the background image section displaying correctly.

I guess what i wanted to ask everyone here is:
A) has anyone else noticed this in the past?
B) should it be something we need to consider moving forward? (as it was the default setting on my new lenovo laptop), or
C) has anyone heard of a work around?

Hopefully this starts a discussion :)

PS - i will say that for designs where you are using a 100% width parent table and a background image this issue does not pose a threat.