Can you ping google.com once you use the modem? You might not be authenticating to the WWW properly and Msn is blinded with connectivity by the modem being unable to do so.

 

How do you ping Google? My internet works fine, as to browsing without any issues, it's just MSN refuses to sign in lol

 

Whats the means of connectivity using the modem? Whats the brand?

 

delete cookies and sign-in without 'remember me'

you're getting a different IP address on the modem-direct connection than you've
been using with the 'switch' (btw: post the make/model please; it's got to be a router)

 

It's a Motorola SB 5101

 

ok, that's your Cable Modem; what is the make/model of the switch you use between the modem and your system?

[edit=jobeard]

The User's Guide shows one version with both USB and Ethernet connections and clearly says you can connection
ONE system to each. This is unusual as more typically it is an either / or setup.

If you use the USB connection, do not place a USB hub between the Modem and the system; it only supports one USB device.

The ethernet connection will allow a ROUTER between the modem and the system, but not a switch nor a hub.
WHY? because your SB5101 does not have NAT support and also does not have DHCP support.​

[/edit]

 

Okay, I'll look into that, thank you. Btw my switch model is a D-Link DES-1005D

 

ouch; good unit but not for your installation; consider: most modems support only onde device

Code:

modem---system

to get more than one, we need a router which provides
NAT and DHCP support

Code:

modem---router---system(4)

how do you get more? add a switch which gives connectivity but relies upon a device upstream with NAT and DHCP services

Code:

modem---router---system(3)
           |
           +----- switch---four more