Update: Worked! I moved all the files in my screeshot folder to a new folder for safe keeping....took a new screeny just now and it made it to my screenshot folder. Thanks to G-452 and you others for help!
Thanks for the replies. It may be that my "screenshots" folder is full. I right clicked on it and went to "properties" and it says "size: 299 mb" and "size on disk: 299mb". So, maybe I maxed it out. I guess I just need to copy all those files and move them to a new folder like "screeshot overflow" or something. Guess I'll try that.