Probably that C2Media is trying to contact its own server to get the necessary files to do an uninstallation (that's only a guess but that's the most logical explanation). If you block a software (any software) from doing what it's supposed to do, then you can't complain if the result is not what you expected
.
As for anti-viruses that detect the sponsor's setup as a trojan, they are just crappy programs in hope to justify their existence. It looks good to say "I detect more viruses than the other". This is pure and unjustified diffamation which is another proof everybody should use a professional anti-virus solution.