tarsnap.conf & ^Q

[tarsnap <tarsnap@infopower.nl>]

I have 2 issues remaining that keep puzzling me, maybe someone can
point out what I'm doing wrong?

1. If I make a backup
( sudo tarsnap -cpf <archive-name> <file-to-backup> ) it doesn't find
the file /usr/local/etc/tarsnap.conf without being directed to it
through the --configfile option.

2. Terminating a running backup through ^Q, seeing it finish cleanly,
and then repeating the same backup command later, gives me a 
<quote>
An archive already exists with the
name "<archive-name>.part"
tarsnap: Error creating new archive
</quote>
Which surprises me, because it's documented as being supposed not to
do this.

Any hints?
Thanks