I am getting this error when I try to apt-get update

Reading package lists... Error!
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://apt.simplexsolutionsinc.com wheezy InRelease: Clearsigned file isn't valid, got 'NODATA' (does the network require authentication?)

W: Failed to fetch http://apt.simplexsolutionsinc.com/repository/dists/wheezy/InRelease  

W: Some index files failed to download. They have been ignored, or old ones used instead.
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/apt.simplexsolutionsinc.com_repository_dists_wheezy_main_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.

When I try to do an upgrade or install I get

Reading package lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/apt.simplexsolutionsinc.com_repository_dists_wheezy_main_i18n_Translation-en
E: The package lists or status file could not be parsed or opened.

I emailed the support folks at simplexsolutionsinc.com (the provider of my VPN) to see if they can fix the errors at their end. 

I assume I could uninstall the VPN from simplex solutions and remove the ppa from apt, do the upgrade and install the software I need, and then reinstall the VPN. 

Is there another way for me to move forward and do an upgrade and some installs without removing the VPN software?

Thanks!

Mark