i am facing a very weird thing on 1.5.3.1.

My installation is a fresh one and imported backup from TT 1.3.1. It is a multi-blog installation. After a period of usage (about 2 weeks), the problem below appears suddenly on certain users but not all:

1. When composing new article, when saving, it will show a "saving now" message and then follow by "saving fail" message. But when I abandon the saving and back to article list, the composing article is already saved and shown in the list! If the first save action of the new compose article was by system, then it will shows 2 files in the list with different contents.

2. When I try to delete an article from the list, it returns an error page:

and when click on browser's back button to previous page, the article is no longer there.

###################################################

Here's a simple test I have done:
1. Installed a new TC with same version in same host.
2. Uses different DB.
3. Performed a fresh setup.

and then I didn't found any error on this new installation... >.<"

Anybody can give help?