Linux Ubuntu 11.10 unable to upload images using swfuploader
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Hi I'm a web developer and we have a user who is having problems uploading some images using the SWFUploader. 
Some of the images are fine and he can upload but there are a quite a few which he can't.
When he clicks to browse the folder it comes up but the images aren't there.

It doesn't seem to be a mime issue or anything to do with the extension being capitals.
The files seem to be a range of sizes as well so that doesn't help.

I've asked the user to update his system and browser same problem. He has tried several different browsers and has also updated his flash.

Doesn't seem to be a virus or anything nasty.
Does anyone know of any other steps I could take.
I would like to try this out myself but we only have windows and a mac and a command based lunix server and he is on Ubuntu 11.10 - Oneiric Ocelot

Any ideas?
Thanks
Richard