LR 3.6: Keywords Not Being Saved to DNG Files

UPDATE

Now seeing brand new behavior, with the original issue resolved automatically (Nice). I assume it has to do with restarting: my computer, Windows 7 Explorer and Lightroom since last night, after having installed, uninstalled and tested several programs.

So now what it's doing is: (IN LIGHTROOM) with DNG / JPEG file pairs, I add keywords in Lightroom and (IN WINDOWS 7 EXPLORER) these DO show up immediately in Tag column but only for the DNG file, NOT for the corresponding JPEG. For the solitary JPEGs (ie. with no corresponding DNG), these JPEGs show keywords normally.

(IN LIGHTROOM) When I look at the path below the image preview in Library - Loupe view, it only shows the filename for the .DNG file, with no mention of the corresponding .JPG filename. So when I go to keyword, is it likely that am I just keywording the .DNG file, and not the .JPG? Is there a way to keyword both at the same time?

Thanks in advance!