Problem with Thumbnail creation

Hi, I recently switched to a new host and ever since, I can’t get thumbnails. The built in uploader doesn’t give me any errors, it just tells me there is no thumbnail if I try to use one, and my old version of photopress gives me this error:
Filetype not supported. Image not resized.Filetype not supported. Image not resized.
Warning: getimagesize(/home/moltenwo/public_html/photoblog/wp-content/images/thumb_newport.jpg) [function.getimagesize]: failed to open stream: No such file or directory in /home/moltenwo/public_html/photoblog/wp-content/plugins/photopress/upload.php on line 305

My host has been trying to fix it, but not having luck, so I thought I would check and see if anyone knew what we should be looking for.

Thanks ??