WordPress MU

Dear all,
After migrating my wpmu to a new server, I've come up to a problem(NOT sure if we had it before migrating).
When I was trying to upload a image from the visual editor by select a local file and click the btn,the TB window behaves like a simply refresh of itself, and no sign of successful uploading there. Checking in the media library will also resulting in nothing. BUT when I check my upload directory on the server, I could find the file was succesfully uploaded to the upload path.
However if I try the same file in the media-new.php, it will works. I could find the file both in media library or my ftp directory.

Please give some advise to solve this weird problem

Could anyone give a clue, please

Also facing the same issue, I'm using WordPress MU version 2.8.4a. Trying to upload media on a new Page (Pages > Add New > Add Media) and the visual editor is not displayed soon after file crunching. The file is uploaded successfully in the blog upload directory but I just can't seem to edit the file on the fly, especially when adding it from a new page.

Any suggestion on resolving this issue is sincerely appreciated.

Can you upgrade to 2.8.6 and try this again? It might be the problem (if it was a WPMU codebase issue) was resolved in a later release. If you upgrade and the problem persists, let us know.

And check your error logs on the server - that's always the first step.

This problem don't repro after I updated wpmu to 2.9.1.

Thanks you guys