Google Webmasters Error

Hello

I am submitting my sitemap to google webmaster tools and some images work but for some i am getting the following error

This is not a valid URL. Please correct it and resubmit.

example:
Parent tag: image
Tag: loc

i have looked for loc and the only thing that says that is the xml,

anybody know whats going on,

let me know

Thank You

http://wordpress.org/extend/plugins/google-image-sitemap/