Hello,
since some day I have problems with the trinity repository.
It started on June 30th with the following message:
W: A error occurred during the signature verification. The repository is not 
updated and the previous index files will be used. GPG error: 
http://ppa.quickbuild.pearsoncomputing.net precise Release: The following 
signatures couldn't be verified because the public key is not available: 
NO_PUBKEY 96C95152F5CFC95C

After updating the key with
sudo apt-key adv --keyserver 
keyserver.quickbuild.pearsoncomputing.net --recv-keys 96C95152F5CFC95C

Since that I get signature errors:

W: GPG error: http://ppa.quickbuild.pearsoncomputing.net precise Release: The 
following signatures were invalid: BADSIG 96C95152F5CFC95C QuickBuild Trinity 
Desktop Environment
W: A error occurred during the signature verification. The repository is not 
updated and the previous index files will be used. GPG error: 
http://ppa.quickbuild.pearsoncomputing.net precise Release: The following 
signatures were invalid: BADSIG 43F1DC4F2B8638D0 QuickBuild Trinity Desktop 
Environment

Is there anything I can do to solve this issue?

Thanks in advance.

Stefan