When you add a Placement.info file to an Orchard module, never forget to set its build action (from under Properties) to "Content"! By default it's "None".
If you build the Orchard solution from Visual Studio, there is no difference. However if the solution is built directly from MSBuild (what's possible e.g. if you run the ClickToBuild.cmd from the source package; hosting providers that give you automatic deployment by pulling from a source control repository do this too) files with the "None" build action won't be included in the build output. This means, that such files won't be deployed either, what in term means that your site will miss those Placement.info files. Not very surprisingly this way none of the shapes whose placement is declared in the missing files will get rendered. All this without any exception or error message; of course, since there was no error: you deliberately have chosen not to specify their placement, didn't you?
Tl;dr: set the build action of Placement.info files to "Content". It's good for you!