I have not been able to find an answer to this problem elsewhere.
Starting last night, the font size in my posts has begun to change -- the font in the first sentence (not just the first line, but the entire first sentence) is the typical size, but each later sentence in that paragraph is a smaller font size.
When I start a new paragraph, the first sentence is in the typical size and then each later sentence in that paragraph is the smaller size.
I write my posts in Microsoft Word, using Times New Roman 12 font, and then I use the "Paste from Word" tool when I insert the post into WordPress.
I am using the Twenty Ten theme.
Any help would be appreciated. Thank you.