Error 426

I am continually recieving the following error while downloading:

426 Error writing to port 48603 on

(Caps indicate my edits. The port number varies between about 48000 & 59000.)

I am trying to download a 9GB+ set of installation files (SuSE Linux 10.1) so that my students can access them locally within my classroom rather than use up the district's bandwidth with internet installations.

This error is occuring every few dozen MB .... sometimes I may get 100 or 200MB downloaded before I get the error.

I have already switched between Active & Passive modes. Active mode didn't let me download anything. Passive mode gives me the errors. I tried checking "Force Server IP for PASV Mode" and unchecking it. No difference.

My computers are behind a Netgear WGT624 home wireless router in my classroom and the school district has much more capable routers at the main office.

Has anyone any ideas on where the problem may lie and how I can get it resolved ? Thanks