probably a firewall issue. Plan B. Go and download Firefox and install it, then try again. As soon as you try to install it, then the firewall might complain, so then you can shut it off for a moment and install firefox, then turn it back on. Now go and submit something. Unlikely to be 'the internet' or a broadband issue. It will be a setting in IE, such as the proxy - check the connection setting in options. Go to the bottom LAN options and look at that. It will show you if you are connecting through DCHP - automatically detecting settings or using a Proxy.
The proxy may be blocking the get/post method. But then as you're posting here it's not likely.
Run Firefox, if it does the same (off a new install) as IE, then discount IE as the problem to a large degree.
Plan C
Try a java powered DSL speed test and see how fast you are running ... this will open sufficient ports to see what's happening.
http://www.dslreports.com/stest?loc=1
You should see a live transmission and speed test, probably a 700 per sec speed (Telstra speed sux)
If that won't run, then I would suspect the router (if you have one). You need to check the settings to see why it's not letting traffic through, probably packet checking issues.
If you dont have a router, then it might be the modem ... pull out the cables (switch off first), this will kill the ISP heartbeat. Restart the router, the modem and the computer and re-boot.
Run Firefox again and see if it cures the issue.
I would think it's a firewall/router problem with its packet sniffing. ooohhh er.
If you break it, pack it all away and pretend you never touched it.
