There are some firefox plugins cause validation error on file upload.

There are some firefox plugins cause validation error on file upload.

case -----------------
1. Install xampp 1.6.3a into WinXP sp3 + IE6.
2. create db "test" with phpMyAdmin.
3. Install drupal 6.6.
4. turn on "upload" module, and verify settings.
5. on /node/add/story, attach file "example.jpg" ... failed.
Error dialog appeared.
> An Http error 0 occured
> /upload/js

what I did -----------------
I use Firefox usually, then try with IE ... It's succeeded.

Then, I try with Firefox and Fiddler.
Server returns succeeded result. But error dialog appeared.

Error is caused by firefox.
I remove all Firefox plugin. and retry ... succeeded.

There are some plugins cause error.

...

I found. "Linkificatin 1.3.5" is cause of the error.