AddMultipleFiles giving error":Item already exists

gururaj_rp

I am invoking workflows in a loop manually using command tools.
For every workflow invoked I attach files using AddMultipleFiles related with the loop.

The first iteration works fine.The files get attached to the task.
But in the second iteration it gives "ERROR:00017: Item already exists" and not attaching the files.

$task->AddMultipleFiles(\@finaldoc_list, "Job:$wf");

Is it anything to do with the array?

Thanks
Gururaj