gallery2上传图片的问题

    今天成功安装并桥接了gallery2，试图上传图片时不成功。后来在服务器上指定了一个文件夹，使用“从本地服务器”添加图片的方式处理，结果又报错了，错误信息如下：
    我已经试了三个图库组件了，还是不成功，失望中……

    服务器平台是cent os 4，uname 信息如下：
    2.6.9-67.0.7.EL #1 Sat Mar 15 06:19:12 EDT 2008 i686 i686 i386 GNU/Linux
    不知哪位大侠能帮我？

Platform Error

An error has occurred while interacting with the platform.
The exact nature of the platform error is unknown. A common cause are insufficient file system permissions. This can happen if you or your webhost changed something in the file system, e.g. by restoring data from a backup.

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Error Detail -
Error (ERROR_PLATFORM_FAILURE)

    * in modules/core/classes/GalleryDataItem.class at line 173 (gallerycoreapi::error)
    * in modules/core/classes/GalleryPhotoItem.class at line 104 (gallerydataitem::create)
    * in modules/core/classes/helpers/GalleryItemHelper_medium.class at line 148 (galleryphotoitem::create)
    * in modules/core/classes/GalleryCoreApi.class at line 1583 (galleryitemhelper_medium::additemtoalbum)
    * in modules/itemadd/ItemAddFromServer.inc at line 177 (gallerycoreapi::additemtoalbum)
    * in modules/itemadd/ItemAddFromServer.inc at line 105 (itemaddfromserver::additem)
    * in modules/core/ItemAdd.inc at line 84 (itemaddfromserver::handlerequest)
    * in main.php at line 231 (itemaddcontroller::handlerequest)
    * in main.php at line 94
    * in main.php at line 83

System Information
Gallery version    2.2.2
PHP version    4.3.9 apache2handler
Webserver    Apache/2.0.52 (CentOS)
Database    mysqlt 4.1.20
Toolkits    Thumbnail, Gd
Operating system    Linux gxy.lzu.edu.cn 2.6.9-67.0.7.EL #1 Sat Mar 15 06:19:12 EDT 2008 i686
Browser    Mozilla/5.0 (Windows; U; Windows NT 6.0; zh-CN; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14