Hello People

I've been dealing with a very annoying problem for a long time now, over multiple versions of Tixati (and probably even different software like BitTorrent and uTorrent and the like).
The problem is that when running Tixati (or any other torrent-program), the internet-connection simply gets terminated at random (a yellow triangle with an exclamation-mark appears on the network-logo in the taskbar).
And the connection also does not recover from things such as terminating the torrent-software, reconnecting the internet or even reconnecting the ethernet-cable (no wifi here),
not even logging out and back into the Windows-account resets the connection. The only thing I can do is restart the whole computer and it will work again.

The amount of time after which it terminates the connection seems to be random, as it could be anywhere from immediately within the first minute of running Tixati, or after half an hour or so.
It also doesn't seem to matter whether or not I use the system or any program. I've tried only using different internet-browsers, or not browsing the internet at all.
I can't even leave the computer running so it can finish a download, it will terminate the connection after some time regardless.

That's also the biggest problem right now, because most of the time I don't really download all that much. It's usually small stuff.
But now I'm trying to download something of significant size, also at a low speed, but I'd have to babysit the computer and restart it over and over again (probably a thousand times) before this download is done, just to maintain the connection.

Does ANYone know just WHAT is causing the connection to be terminated when using Tixati (or other torrent-services)?
Oh, and also; It happens with nothing else. I've used services that let you download unlimited amounts at unlimited speeds, and it could just go at like 100MB/s forever.
So there's no real limit from my ISP or the router (although I wouldn't exclude a router-setting I don't know of).
And also, I HAVE been able to use Tixati and similar software without problems before on this same computer. This problem just appeared out of nowhere.
I was hoping jumping from an older version to the latest (I hadn't updated in a while) would wipe this problem, but it's still the same.
There's probably no real problem with Tixati itself, but there's something about torrent-software that breaks the internet-connection.
Also note that it does NOT break my entire internet-connection to the outside (other devices and the router keep working). It purely disables something internally on this PC.
Maybe it has to do with some sort of router/firewall-setting?... I use a Netgear-router and COMODO's anti-virus and firewall.
It's probably not COMODO's doing, though, cause it would just block the software rather than breaking the whole internet-connection.
But I'm just throwing some possibilities out there.

Thanks for reading.

1) network drivers
2) some unpnp issue - disable that?
3) some werid protocol from av. leave only TCP/IP in connection proprties
4) half open tcp connection limit in windows
5) try to torrent from linux live cd
6) update router firmware
7) if connected directly (not through router) problem still exists?
8) combine 5 and 7
9) dust clean your pc/network card
10) test wire
...