When I download files from our FTP server using my notebook on the company LAN, the download speed was 10 to 20 kbits/sec, which is very slow compared to using a local desktop, where the download speed was closer to 150 kbits/sec. There was no problem downloading files from external Internet sites. The IT guy and I puzzled over this problem off and on; it was annoying but not critical. I tried different FTP clients but there was no difference. Then the IT guy suggested turning off Deterministic Network Enhancer (DNE) (open Local Area Connection Properties and clear the DNE's checkbox). When I restarted my FTP client, the download speed improved to the same level as the desktop.
It turns out that DNE was installed with the VPN software on my notebook. I have to remember to re-enable the DNE when I use the VPN. Still beats me why it only affected FTP downloads from our local server.
14-Nov-2007. It's not DNE. When I reset the network adapter after I start the FTP client, the download speed improved. IT Guy thinks my notebook may require an updated network adapter driver or BIOS.
Updated my Asus BIOS from 214 to 218 and the networking problem seems to be fixed.
15-Nov-2007. It's not the BIOS either. Updated my Realtek RTL8160/8111 network adaptor driver from 5.666.301.2007 to 5.680.1023.2007 and I'll see what happens the next time I restart my notebook.
16-Nov-2007. Success! My notebook download speed went past 130 kbits/sec on the first go.