[trinity-users] trinity-keyring overwrites sources.list.d -why?

Web page instructions for Squeeze say to use: deb http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity-v3.5.13/debian squeeze main I put that (and the other 3 TDE lines) in /etc/apt/sources.list.d/trinity.list manually. When "trinity-keyring" gets installed it actually writes to (and overwrites if already exists) that file with this entry: # Trinity repositories deb http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity-v3.5.13/ubuntu squeeze main deb-src http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity-v3.5.13/ubuntu squeeze main deb http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity-builddeps-v3.5.1… squeeze main deb-src http://ppa.quickbuild.pearsoncomputing.net/trinity/trinity-builddeps-v3.5.1… squeeze main It will work like that but not till after another apt-get update (that played havoc with my custom install scripts) I had to strip the deb package down to find out what had altered my list. ?