I don't see how that could happen.
Turn off spider url's and see if it displays however look at the code here
Now its obvious you have a file based avatar so it follows this code portion
$userprofile[6] = "<img src=\"{$Globals['vbulletin']}/$vboptions[avatarurl]/avatar{$cuserid}_{$avrev}.gif\" border=\"0\">"; // Avatar
SO WHATS YOUR VBULLETIN URL SET TO IN ADMIN FORUM SETTINGS
Code:
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