Download process stops - only fraction of file is downloaded

What happens:

1. Start download (from file hosting)
2. Speed ok, download progress bar is filling
3. Some time passed...(no alerts)
4. Speed = 0, a fraction of file is on disk.

Notice:

1. I tried to download using Tor 0.2.1.26 and 0.2.1.27 different files from different hosts with almost the same result: 60-65 mb downloaded on disk

2. When downloading without Tor (Tor not started), using Google chrome browser, all is ok.

System parameters:

1. OS Windows XP 5.1.2600
2. Antivirus Avira (webGuard off, firewall off)
3. Windows firewall is off
4. Event ID 4226 Patcher applied
5. Mozilla adjusted: network.http.keep-alive.timeout:600 (300ms default is OK usually, but 600 is better.) network.http.max-persistent-connections-per-proxy:16 (Default is 4) network.http.pipelining:true (Default- false. Some old HTTP/1.0 servers can't handle it.) network.http.pipelining.maxrequests:8 (No default) network.http.proxy.keep-alive:true (Default- true, but double check) network.http.proxy.pipelining:true (Default- false) - See NOTE1 below.

QUESTION: What can be done to fix the problem?

Trac:
Username: alexnv