Thanks for your response.
I am trying to put together a file upload site similar to yousendit.com and i have a php script that provides the functionality. This uses the standard browser http. I have been experimenting with the security side of things thanks to your excellent guides and have got as far as mod_security scanning the files on upload but with this problem of it now rejecting files over 350M.
So if i can get this to work on larger files, i would be almost there...I might need to get someone with more programming skills than myself involved , I realise that.
thanks for any help in advance.