[winswitch] installation problem with Ubuntu

[repod]

Hello, this is my first post, I didn't find a solution in the archives or
the web, sorry if I missed it. I'm trying to install on Ubuntu Precise
12.04. I added the winswitch repository, and ran apt-get update. It ends
like this:

Ign https://winswitch.org precise Release.gpg
Ign https://winswitch.org precise Release
Ign https://winswitch.org precise/main i386 Packages/DiffIndex
Ign https://winswitch.org precise/main TranslationIndex
Err https://winswitch.org precise/main i386 Packages
  server certificate verification failed. CAfile:
/etc/ssl/certs/ca-certificates.crt CRLfile: none
Ign https://winswitch.org precise/main Translation-en_US
Ign https://winswitch.org precise/main Translation-en
Fetched 160 kB in 27s (5,879 B/s)
W: Failed to fetch
https://winswitch.org/dists/precise/main/binary-i386/Packages  server
certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt
CRLfile: none

E: Some index files failed to download. They have been ignored, or old ones
used instead.