Upload not working

I chose to move my WP blog to another host a couple of months ago. This was my first time moving a WP blog.

It took me quite a while before I managed to get the photos to show up in my blog but I managed somehow. Although now the upload is not working. If I want to create a new post and I want to upload a pic, only the no-pic-icon shows up after the upload in the media library.

So, Im a WP novice. Plz help me ??
Thanks