RMagick help

I can run the ImageMagick command (convert /path/to/file/temp.pdf
/path/to/file/temp.jpg) and it works fine.
I can run script/console and do this - image = Magick::ImageList.new
/path/to/file/temp.pdf, and it works fine.

However, when I run that same code in rails in development mode (using
phusion), I get this error.

Magick::ImageMagickError (Postscript delegate failed
`/Users/andrewthorp/Sites/gladhandle/crm/public/files/users/3/assets/logos/temp.pdf’:
No such file or directory @ pdf.c/ReadPDFImage/612):

Anyone who can help me would be greatly appreciated…