Ok, I did some quick tests. You are right about this it was only 2.5 Mb, that was one of my last additions yesterday , anyway, I've modified that parameter to 20 Mb but I'm still hitting the 8 Mb limit imposed by the ini file .
I think I didn't mentioned this before, but I have already tried the phpinfo() page to gather info, that's how I learned the 8Mb defined on php.ini file.
Anyway, perhaps I will have to implement the upload mechanism via CGI ...
any other idea before dropping PHP on this part?