A perpetual question it seems.
Some answers are given here:
http://chipmusic.org...n-i-test-a-sid/
Your instincts serve you well, DO NOT TRY ANOTHER SID IN THE FAULTY ONES SOCKET (see last post on that link)
I've read of a fair few mystery stories on apparent non-working SID's. Don't give up hope yet. :)
I've extracted a couple of SID's before, i just used a flathead screw driver and slowly levered it out bit by bit end by end, took a while but the legs snap/bend if you go too rough/quickly.