My Mozilla file upload is slower than IE

I have an application that uploads large gigabyte sized files via our T1 
intranet.

My mozilla 1.7.7 browser gets about 150KB/sec upload. My IE6 does about 
750KB/sec.

Now to get IE6 to do 750KB/sec, I had to change the IE registry entry ala

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
"TcpWindowSize"=dword:00008000

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet 
Settings]
"SocketSendBufferLength"=dword:00008000

Is there something similar to unleash Mozialla's upload performance?