[Plugin: NextGEN Gallery] Flash Uploader Not Working

I recently installed NGG and attempted to upload several photos to a gallery. For some reason, one photo uploaded, but the rest did not.

Each time an upload failed, it showed the progress bar, but then skipped to some page that I couldn’t read, and then quickly moved back to the upload page, which reported “0 Successful Uploads”.

I have double checked the folder permissions, file sizes and deactivated all other plugins, but nothing has worked.

I also tried uploading images to one of the galleries that was empty, and got this message:

“gallery/plants contains no pictures”

Once I disabled the flash based upload and everything seems to be working fine.

Has anyone else had this issue, or know how to fix it?

NGG Version: Version 1.5.5
WP Version: 2.9.2
Firefox Version: 3.5.9