[lovelyman_x]

First problem:
Login admincp==>Vbulletin Option
In User Registration Options,choose yes at Display Avatars
To show avatar in Member List:
Vbulletin Option==>User Listing & Profile Viewing .In Member List Field Options choose yes at Avatar
To show the default icon for no avatar:
Open file includes/functions_showthread.php
Find:

if (empty($avatarurl) OR ($bbuserinfo['userid'] > 0 AND !($bbuserinfo['showavatars'])))
{
$show['avatar'] = false;
}
else
{
$show['avatar'] = true;
}

Replace with:

$show['avatar'] = true;

if (empty($avatarurl) OR ($bbuserinfo['userid'] > 0 AND !($bbuserinfo['showavatars'])))
{
$avatarurl="$stylevar[imagesfolder]/avatars/noavatar.gif";
}

Save and re-upload the file to yourserver.
Then upload the file noavatar.gif to folder [imagesfolder]/avatars/
Have fun!