Networking :: ADSL Broadband Throttling File Download ?

I'm not getting file transfers that utilize the max bandwidth of my ADSL broadband. I have a 512 kbps line (I know that's not broadband in most places, but such is the option available to me), and I usually get download speeds of 55-60 kbps. Since the past couple of days, this has dropped to an abysmal 2-3 kbps. So I used [url] to test my download speeds, and they were as expected (i.e. the usual 55-60 kbps). I also used the speed test page of my ISP, and that too, gave the usual results. There has been no throttling from the ISP, as I confirmed from their help desk.

Also, web pages open fine. It's only when I'm downloading a file (Yeah, web pages are also files, but what I mean is compressed archived files; .rar, .tar.?g* et.al.) that I can't get the desired speed. I haven't changed the resolv.conf file, not have I made any other changes that might cause this. I use ppp to dial-up to my ISP, and use the pon and poff scripts that ppp provides. I have a peers file configured for my ISP, which again, I haven't edited.