calibre id not working as part of save template

[42lizard]

I have my send to device template set to {title} - {authors} - ({id})

but for any book sent to my xteink the id is -1 in the resulting filename.

for example:

Storyteller's Death, The - Ann Davila Cardinal - (-1).epub

instead of

Storyteller's Death, The - Ann Davila Cardinal - (6188).epub