My install seems to do that. I do have them listed with the "Details" option for viewing. But as I select files, or folders, the number changes and the size changes with it.
Maybe a snipping tool picture attached using the paperclip on advanced replies would help explain your situation.
Details pane works half-way but better than nothing. It displays the total size if it's 15 items or less. If it's over, you can click "More details" but it won't display anything if it's way over 15. Secondly, it takes ~ 1/2 inch space. While status bar is unused. Is there a setting to bring the XP function back? it seems Saltgrass has the feature on. I have "Display file size information in folder tips" on in Folder Options.
Are you sure? I have folders with hundreds of items in, still lets me click 'more info' to see the total size when I select them all (but not when a subfolder is selected).
Alternatively, you can select the necessary files and go to properties on the context menu, though that's not ideal.