I had this prob too guys to solve this prob. you have to edit one file.
edit File: -
/arcade/funtions/functions.php
Find
Code:
$check = getimagesize($member_avatar);
$avatarwidth = $check[0];
$avatarheight = $check[1];
And Delete these codes
Find
Code:
<img src='{$member_avatar}' border='0' alt='' width='{$avatarwidth}' height='{$avatarheight}' />
and Change {$avatarheight} with the Height of avater you want same with Width.
Eg.
Code:
<img src='{$member_avatar}' border='0' alt='' width='120' height='120' />
I Hope i didn't made mistake And enjoy.