OK, there are two limitations to worry about for WAN users (not knowing if you are internal or not). There is of course MAX size, which is what you've changed, but also is the MAX UPLOAD time, this is the timeout which is allowed for the MAX SIZE to get uploaded, if you're on dialup (external) then this will also be an issue. I have no idea how to change it, but it gives you somewhere to start looking.
Terry
HINT-This is a php setting, so it's prolly configured somewhere there.