Avatar Plugin + Edublog theme +WPMU 2.7= Not Working

1. the avatar displayed on the front page links to no file > http://xxx.tld/avatar/user-1-48.png

2. What file do i have to paste the code "<?php echo get_avatar(1,'32','identicon'); ?>"

comment.php or avatar_comment.php ?

3. It seems edublog theme is not avatar-ready so where to place the above code (in comment.php or avatar_comment.php ?)

4. I can upload the image but the image is not displayed in either admin page or front page.

FYI, it is not working for every theme I use either.

Please advise.