apt-get update not working in terminal

[sudeshkagrawal]

All was a few days and suddenly apt-get update stopped working on terminal.
I am under a proxy which requires authentication.
My apt.conf file:
Acquire::http:roxy "http://netmon.iitb.ac.in:80/";
Acquire::ftp:roxy "ftp://netmon.iitb.ac.in:80/";
Acquire::https:roxy "https://netmon.iitb.ac.in:80/";
ACQUIRE {

http:roxy "http://<username>:<password>@netmon.iitb.ac.in:80/"
}

APT
{
// Options for the downloading routines
Acquire
{
http
{

No-Cache "true";
};
};
}
//Acquire::http:roxy "http://netmon.iitb.ac.in:80/";
There shouldn't be a problem with the code in apt.conf since I have been using the same since 2 years.
My .bashrc is also set to export the proxy. I am not sure but it is probably to export the proxy to other environment?
Update is working through synaptic. Currenlty I am using Synaptic to update.
But local sites have stopped opening firefox,chromium and google chrome concurrently i.e. they started happening at the same time.
Before the problem started the status was:
update worked fine
local sites opened in all browsers
but SSL sites (like mail.google.com) did not open in chromium and google chrome though they opened in ff. I used to get error 107 and this problem is still not fixed

OS: Ubuntu 12.10 (Linux 3.5.0-25-generic)
I have windows 8 installed side by side on a different partition.

[Mark_in_Hollywood]

Can you run

fsck

from the grub OS selection screen? That screen appears before the screen where you would enter your password.

[darkcrimson]

That really stinks you can't apt-get update. Try this and post the output if errors are received:

wget http://gb.archive.ubuntu.com/ubuntu/dists/quantal/Release

If there's an issue with the proxy not resolving or requiring auth, we'll see it in the output. Hope this helps!

[tgalati4]

Or your proxy administrator has slapped some rules that are limiting your bandwidth. Talk with your IT folks.