Unable to process spool options file?

[Ken A]

What is the correct syntax for auto-delete in a per user 
.user.qpopper-options file?

I've tried:
set auto-delete = true
set auto-delete = 1
set auto-delete

I keep getting an error: "Unable to process spool options file"
I'm using latest qpopper 4.0.8
Qpopper does have permission to read the file.

Thanks,
Ken A
Pacific.Net