TreasureChest phpThumb error

Can’t find an answer to this one. I’m building a site with Treasure Chest but I get this error when it attempts to create the thumbnail:

phpThumb() v1.7.8-200709161750

Usage:
/`mavarts/assets/snippets/treasure_chest/images/phpthumb/phpThumb.php?src=/path/and/filename.jpg
read usage comments for details

I have TC installed and working properly on another site running on the same server (Apache).

If anyone has seen this before can you point me in the right direction.

Thanks

I have moved a site from one hosting account to another and I also get a similar error.