Thumbnails no longer working after server move

Hello

After moving hosting servers all thumbnails for all existing galleries have stopped displaying, clicking where the thumbnail should be still does display the full size image, all other functioning of site appears good.

Site url: http://www.xlerate.net/?page_id=4174

Uploading new albums works fine
Uploading new images to pre-server move existing albums do not work.
Re-scanning folder for images does not bring them thumbnail back.
Manually editing each image does not bring the thumbnail back.

Any help would be great please