serviio plugin install fails, can't verify dropboxusercontent.com certificate

I get this error trying to install serviio:

root@unraid:/boot/plugins# installplg serviio-1.4-1jr-cache.plg

installing plugin: serviio-1.4-1jr-cache

file /boot/packages/jre-7u2-i586.txz: downloading from http://dl.dropbox.com/u/73389880/jre-files/jre-7u2-i586.txz ... Cookie coming from dl.dropboxusercontent.com attempted to set domain to dl.dropboxusercontent.com

Cookie coming from dl.dropboxusercontent.com attempted to set domain to dl.dropboxusercontent.com

ERROR: cannot verify dl.dropboxusercontent.com's certificate, issued by `/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA':

  Unable to locally verify the issuer's authority.

To connect to dl.dropboxusercontent.com insecurely, use `--no-check-certificate'.

I can't connect with --no-check-certificate because the package installer is issuing the commands.

This thread describes how to update certificates: http://lime-technology.com/forum/index.php?topic=31619.0

However, the certificates it installs are over a year old and I don't know where to find a newer set of certificates that might have an updated dropbox certificate.

Any advice would be appreciated.

- Eric