I don't know if this is related, but... I've been having a terrible time with combining posting an image (or two) and Post from Word. I crafted a post to wrap around two images (one on left and further down the page, one on the right.) With html, this used to be a pretty easy task. It took awhile to figure out, but it finally all came together. Then when I hit the Edit button, it loses some of that. It lost the align=left (or align=right) as the case may be. Completely dropped those.
Related? I have no idea.
Word produces terrible output, the editor attempts to correct this, with limited success. There should be no reason your image tags are loosing the align property. I will look into it some.