if you put yer mouse pointer over an image and right click, then select from the small window menu "view image info" and click on it, the dimensions of the image are listed. you might see something like "745p x 834p". the first number is all we're interested in - it's the image width, it needs to be 640 or less.
if you think you've resized your image correctly, and go back to look at it again, refresh/reload the page - this is important as you need to update your computer's "cache" memory and have it show you the newly resized image. if you don't do this browser refresh/reload you'll still be looking at the old, larger image.
there are too many issues with the "new and improved" photobucket. we recommend not using it and go with
www.imgur.com instead. there's a how-to about using imgur in a sticky post at the top of this forum. imgur is free, allows auto image resizing on upload, and is much faster and easier to use than that "new and improved" photobucket.