There's a fix available for that over at VBulletin, Cary posted it. Worked for users with 2.2.5, 2.2.8, and 2.2.9 Backup your member.php file, rename it to something else for safe keeping.
Open up your member.php file.
Find the line:
Code:
$birthday = @date($calformat1,mktime(0,0,0,$bday[1],$bday[2],$bday[0]));
Change it to:
Code:
$birthday = @date($calformat2,mktime(0,0,0,$bday[1],$bday[2])). ", $bday[0]";
Make the change, upload member.php and then refresh the user profile you're looking at. It will now appear with the proper year. Just installed this and it fixed the problem.