I just did a post where I did a direct attach. 5 pictures went "invalid link" and the 6th posted ok.
Not sure what I did or didn't do wrong or right on either.

The one thing I am sure of is once a picture attaches to a post you can not use it in another post, even if you rename it on your computer. I have not tried reloading it to the computer from the camera. Does the DSC00XX just carry along no matter what?

Also, If I rotated the picture in my computer file the rotation does not carry along when I upload to post. Not sure if the only thing I can do is to shoot all pictures in landscape format and post that way. Portrait format is just not going to happen?