Requirements
spd needs the following packets on Debian Lenny:
- perl
- gnupg
- libgnupg-interface-perl
- libdigest-md5-file-perl
- libmail-sender-perl
you may find the needed packages for Debian Etch at
deb http://sozial-inkompetent.de/debian binary/
Suggestions
I recommend using a GPG-Agent like gpg-agent or seahorse.