No differentiation among users

I installed this plugin and encountering the following problems:

1) I saved the save image as my “Default” and “Yours” image. Than this image was shown in front of each and every comment on the web site, even if the authors were other users.

2) Than I deleted the “Default” image and left my one as ‘Yours’ image. In this case some strange pattern appeared everywhere in place the image thumbnail.

3) Than I saved the default-user-image.png as my “Default” image, I also left my image saved as “Yours” and now I can see only this default image everywhere. In front of comments posted by me and in front of comments posted by all the other guys.

I’d appreciate your assistance to resolve this.
Regards,
Janos