Upload Size Limit

Hello !

I have a Red Hat 9.0 server with Apache 2.0 and PHP 4.2.2.
I try to upload (with HTTP method) some files with a size superior to 512Kb,
and it doesnt work.
I have an error from my browser wich says "impossible to show this page".
If I put an file inferior at 512Kb its ok

I checked in php.ini that
upload_max_filesize = 2M

So where is my problem ?

Thanks for your help;

Regards,

Eric VIALLE