Folder and file names not showing

Laugh at me for using Windows XP if you must, but here's my problem: half my folders I view with the content as thumbnails are no longer allowing me to see the names of folders and files, unless I switch to a different view. This makes it hard to find folders without specific images in them.
As far as I know there's no reason for this and no obvious option to click to bring them back, and it's impossible to find the answer through Google (if there is one).

Any ideas? The only hint I have is that the most recent one got that way by popping up while I was typing.