Internet connection completely dies if I open too many browser tabs at once... WHAT?
 

Maybe there's a logical reason for this, but I don't understand why it's happening. If I'm browsing an art site, for example, and I'm speeding through thumbnails by wheel-clicking each one (to open in a new tab in Firefox), my connection will completely die and the tabs fail to load. Any further attempts to open windows report "server not found" errors and any active downloads/transfers will abort.

Oddly, any running instant messaging programs will still function as normal, but if I exit the program and then try to reopen it, it won't connect.

It takes anywhere from 30 seconds to five minutes for the connection to be restored (I just have to wait), and then things work fine. My wireless connection always reports signal strength as Excellent, and says it's connected despite the problem. Resetting the wireless router has no effect, nor does plugging into an ethernet connection.

Any ideas???

Could be your connection being saturated with so many requests, or your ISP throttling your connection. I doubt it's anything to do with your hardware or software.

Is that feasible? This has only just started happening in the last few weeks, and I've been on my current ISP for about six months.

Are you running a firewall, and if so, what kind?

I'm not behind a firewall. And like I said, I've been living here since the summer, and I'd had no problems up until a few weeks ago, and no settings have changed that I'm aware of.

Yeah, I think that is feasible. All internet browsing (http protocol) occurs over a few ports that are set. That way, it is possible for them to throttle your internet for those ports should they detect what they might determine is unusual behavior (several simultaneous page requests can potentially look like a browser-refresh DDoS attack).

Not too long ago, (a couple weeks really), the 7chan and 4chan people raided several "offending" websites, bringing them down with a variety of different attacks. One of the easiest ones for an attacker to implement was a refresh-DDoS attack.
I would not be surprised if your ISP was thinking that they were cool if they could prevent these sorts of things from happening.

Out of curiosity, who is your ISP?

Probably the best thing for you to do right now is to actually contact your ISP and ask them what is going on.

All internet services are managed through my landlord, who happen to be bastards, and I've already talked to them about this, and their only answer is "it's all on your end."

Reckon you can test your PC on another internet connection, and another PC on your current connection, and see if the problem recurs?

Yeah, the same thing happens to my roommate's computer, with identical results. I'm almost positive it's solely this connection. I'm not exactly certain how to diagnose this issue and explain it to my landlord/ISP in a way they'll understand and actually do something about it.

Do you know who your ISP is?
Lets just start there.

No, I'll need to get that info from my landlord.

http://www.showmyip.com/
Sorry. I should have linked that earlier. That website gives all sorts of details about your connection, including IP address, ISP, etc.

Cool.
ISP is Internet Dynamics, Corp. (idcnet.com).