www.u-tea.com更换主机后，顺便升到了1.0.1，上传图片时报如下错误。但是图片还是上传了，没有缩略图生成
Exception message: imagejpeg(): Unable to open './gallery/2/previews/2-30.jpg' for writing
Error code: 2
-- Backtrace --
/home/frog/html/plog/class/gallery/resizers/gallerygdresizer.class.php(306): imagejpeg
/home/frog/html/plog/class/gallery/resizers/gallerygdresizer.class.php(56): gallerygdresizer.save
/home/frog/html/plog/class/gallery/resizers/galleryresizer.class.php(151): gallerygdresizer.generate
/home/frog/html/plog/class/gallery/dao/galleryresources.class.php(385): galleryresizer.generate
/home/frog/html/plog/class/gallery/dao/galleryresources.class.php(498): galleryresources.generateresourcethumbnail
/home/frog/html/plog/class/action/admin/adminaddresourceaction.class.php(78): galleryresources.addresource
/home/frog/html/plog/class/controller/controller.class.php(305): adminaddresourceaction.perform
/home/frog/html/plog/admin.php(39): admincontroller.process
Exception message: imagejpeg(): Unable to open './gallery/2/previews-med/2-30.jpg' for writing
Error code: 2
-- Backtrace --
/home/frog/html/plog/class/gallery/resizers/gallerygdresizer.class.php(306): imagejpeg
/home/frog/html/plog/class/gallery/resizers/gallerygdresizer.class.php(56): gallerygdresizer.save
/home/frog/html/plog/class/gallery/resizers/galleryresizer.class.php(151): gallerygdresizer.generate
/home/frog/html/plog/class/gallery/dao/galleryresources.class.php(417): galleryresizer.generate
/home/frog/html/plog/class/gallery/dao/galleryresources.class.php(499): galleryresources.generateresourcemediumsizethumbnail
/home/frog/html/plog/class/action/admin/adminaddresourceaction.class.php(78): galleryresources.addresource
/home/frog/html/plog/class/controller/controller.class.php(305): adminaddresourceaction.perform
/home/frog/html/plog/admin.php(39): admincontroller.process
Exception message: Cannot modify header information - headers already sent by (output started at /home/frog/html/plog/class/object/exception.class.php:37)
Error code: 2
-- Backtrace --
/home/frog/html/plog/class/view/view.class.php(172): header
/home/frog/html/plog/class/view/view.class.php(309): adminresourceslistview.sendcontenttype
/home/frog/html/plog/class/view/admin/adminview.class.php(106): view.render
/home/frog/html/plog/class/view/admin/admintemplatedview.class.php(36): adminview.render
/home/frog/html/plog/class/view/admin/adminresourceslistview.class.php(104): admintemplatedview.render
/home/frog/html/plog/class/controller/controller.class.php(325): adminresourceslistview.render
/home/frog/html/plog/admin.php(39): admincontroller.process
pLog Admin
