Custom images won't appear as a gani param

[cheatbobb]

PHP Code:

setani("2007_w_shovel1","2007_w_shovel_1a.png"); 


The image shows up in GraalShop fine, and the gani shows perfectly using any of the default images. But when we use a custom image such as the attachment, it won't show.
/find 2007_w_shovel_1a.png returns:
images/2007_w_shovel_1a.png: downloadable, 1530 byte, 2007-01-05 12:41:36
It's a 256-colour PNG. (It does show up when inserting the name of the image in the gani instead of the param. The gani is recieving the name of the image correctly as it shows up correctly if you add a showimg to the script.)

Anyone know what the problem could be?