getimagesize(宽度和高度）的结果是'；在PHP中不正确

我遇到了getimagesize()的问题。当我上传图像时会发生这种情况，但是。。只是有时。

脚本应该检查化身（个人资料图片）的图像大小。如果低于或等于200px X 200px，那没关系。

我还没有完成脚本，缺少一些安全方面的东西。但我完全不明白为什么会发生这种事，为什么这种事只是偶尔发生。

我的脚本：

//UpdateAvatar
if(isset($_FILES['uploadAvatar']) AND (isset($_SESSION['user']) OR isset($_SESSION['dev']))) {
    //Upload
    $uploadDir = "../img/avatar/";//relative path (we're in php folder [one step back then img])
    $avatarExtension = pathinfo($_FILES['uploadAvatar']['name'], PATHINFO_EXTENSION);//avatar extension (jpg,png,gif)
    if($avatarExtension == "gif" || $avatarExtension == "jpeg" || $avatarExtension == "jpg" || $avatarExtension == "png") {
        $_FILES['uploadAvatar']['name'] = $LoginName."_avatar".".".$avatarExtension;//build new name (max 4 different avas [png/gif/jpg/jpeg] for one user)
        $uploadFile = $uploadDir.basename($_FILES['uploadAvatar']['name']);//'name' is the key (index) of the array
        $uploadFileRes = getimagesize($uploadFile);//resolutionArray = 0 => width | 1 => height
        if(($uploadFileRes[0] <= 200) && ($uploadFile[1] <= 200)) {//250x250
            if(move_uploaded_file($_FILES['uploadAvatar']['tmp_name'], $uploadFile)) {
                //Uploaded
                $newAvatarSql = "UPDATE UserLogIn SET Avatar = '$uploadFile' WHERE ID = '$rcSID'";
                mysql_query($newAvatarSql);
                $Avatar = $uploadFile;
            } else {//UploadFailed
                $ucfg_error_msg = "<span title='"ServerSide failure'" onClick='"killErrMsg(this)'" class='"ucfgErrMsg'">Upload failed!</span>";
            }
        }else {//FileResolution  >(200x200)
            $errImageSize =  $uploadFileRes[0]." x ".$uploadFileRes[1];
            $ucfg_error_msg = "<span title='"Your Avatar had: $errImageSize'" onClick='"killErrMsg(this)'" class='"ucfgErrMsg'">Avatar resolution was<br />greater than 200x200!</span>";
        }
    }else {//NotSupported Extension
        $ucfg_error_msg = "<span title='"Supported: *.png | *.jpg | *.gif'" onClick='"killErrMsg(this)'" class='"ucfgErrMsg'">File-Extension not supported!</span>";
    }
}else {//NotLoggedIn or no Avatar submitted or "fresh Script" => No real error // but blank for JS
    $ucfg_error_msg = "<span class='"ucfgErrMsg'"></span>";
}