I have a modem cable connected to internet 100% of the time.
I also have a D-Link router, DI-525.
I been using BitComet for some years without any problems at all.
For the last 3 days, whenever I start a download with BitComet, my internet stop working for 10 secondes, I can see a pop-up in the icon tray saying “A Network Cable Is Unplug”. After ~10 secondes, the internet start working agains and the download start but only last like 1-2 minutes then once again, I get “A network cable is unplug” and the stop switch to ‘stop’. Everything that is using internet stop having access to Internet. If I dont start a torrent download, I don’t have this issue of network cable or anything else.
Try hooking your PC directly to the modem and see if you still get this problem.
If you don’t, then you’ve found the guilty party.
In that case you’ll have to try and re-flash it, maybe with a newer version of the firmware. Sometimes, even a hardware reset of the device might do it.
If you still do have a problem, it might be your LAN card or your modem. (I’m assuming you have already checked the cables linking all the devices.)