Eventually I managed to establish an account on Seeking Alpha and to post my comment:

http://seekingalpha.com/article/2522485-poet-technologies-revisited#comment-40917035

However, while I understand that they want you to have an account in order to post comments, I have no clue why you cannot read them without an account. If you are not logged in, you are not even told that there is a comment section! Or is it just me using Linux and trying three different browsers?