A guide is a thin blue line on your design canvas along which you can align slide objects. If you drag an object close to the line, the object snaps into place. In this way objects on multiple pages are positioned in exactly the right place. I use them to mark slide borders, and more importantly the vertical center of my drawing canvas when it does not coincide with the center of the screen.
It is very important that these drawing guides stay exactly in the right location, and this is the issue. As soon as your cursor comes anywhere near a drawing guide, PowerPoint will make moving the actual drawing the priority. So if you try to straighten out an object that is a little bit off and want to fixate it against the guide, PowerPoint moves the guide rather than moving or resizing the object.
xScope (affiliate link) is an app for Mac that allows you to draw screen guides independent of the underlying application. The good news: PowerPoint does not move your guides anymore. The bad news, objects do not snap, you have to make sure manually that they are perfectly aligned. One other comment, the app lets you decide where to draw lines and where not when you use 2 screens. xScope does not allow you to manage this on 3 screens.
The app costs $30 and this because the guide feature is part of a full set of tools for graphics designers: measurement rulers, crosshairs, iPhone mirroring, screen shots. Most of these features I actually do not use. As a professional presentation designer, the $30 was money well spent just to sort out the drawing guide issue, I guess for most other people it is not.
Does anyone know cheaper alternatives to solve PowerPoint 2011 screen guide locking?