I Can't Upload The Specific Number Of Pictures.....

This happens to most people.

1) Sometimes these uploading errors occur because there is something wrong with the imagens that you are tring to add. It may not necessarily be a problem that you can directly see. Just an internal error with the image.

2) From my experience, the mais imagens you add at once, the mais get lost. When bulk uploading (for screencaps etc), I never upload mais than about 200 at once and usually one or two imagens get lost in the uploading process. Given that you are uploading mais than 600 at once, mais imagens get lost in the uploading process.
My conselhos is to not load that many at a time. Divide your uploads up in order to prevent that many imagens getting lost.