Mind that 0.025" square posts are too large for IC sockets. You'll have to replace the socket with female header strip.
Tim
I've noticed that. I updated my message after a bit of retesting. When I use the square, low quality headers like the one I linked an image of above, these are my results:
Solderless breadboards: Fine.
Stripboard/pad per hole board: Fine.
Sockets: Not so fine.
Now, it so happens I have made a few of these DIL replacement parts recently and posted them here. I have those cheap headers on them. In fact, the 8 pin one (555) can be inserted into a socket, but only with excessive force. That's why I agree not to use them, I expect it is damaging the socket. For 16-pin versions, it's even harder and I expect the damage is even worse.
Some of my experiments so far (555, 741, 74151):