iTunes store, MSN messenger, Software Updates, Dropbox cannot connect

Hi,

Do you have any proxies selected in Network preferences? If you do, try unselecting them and retrying the problematic applications.

Hi,

Before reinstalling, you might want to try deleting the Network preference files and resetting your preferences in System Preferences > Network afterwords.

This post (and one a few below it) mentions some of the files you'll need to remove:

http://discussions.apple.com/message.jspa?messageID=8028273#8028273

Did you check the post towards the bottom as well?

On 10.5.4, the pref files were named in a different manner, I deleted the following files from the following folder (after backing them up!!!):
Files:'com.apple.network.identification.plist','NetworkInterfaces.plist','com.ap ple.airport.preferences.plist'
Folder: /Library/Preferences/SystemConfiguration/

Hi,

...That folder doesn't seem to exist...should I worry?

It sounds like you are just looking in the wrong location (I hope!)

A path starting with '/' means from the top root level of the drive. I.e.:

Hard drive > Library > Preferences > SystemConfiguration

and not this path:

Hard drive > Users > YourUsername > Library > Preferences > SystemConfiguration

Hmm, if you didn't reboot after deleting them, give that a go - you should need to recreate your setup in Network preferences when it's back up.

I'm hoping the re-setting up of things will help.

Edit: You aren't running any kind of internet protection software are you? (Such as Intego, Little Snitch, etc.)

Hi,

Are you using the iMac restore DVD that came with your computer, or a retail copy of Leopard, or some other disk?

Having exactly the same problem and very frustrated!

I too am having a problem. It seems to have started after the last Software Update to my MBP.
Although I am connected to the internet, my MSN Messenger for Mac won't connect.
I get a message saying "Sign in to MS Messenger failed, because the service is not available, or you are not connected to the internet".
I have checked that the service is available,(it is) and I am connected to the internet.
The funny thing is, after failing to connect with my MBP, I tried my iMac, and that too wouldn't connect.
When I tried the iMac again this morning, it was OK, but as soon as I try the MBP, the problem appears again, and then the iMac won't connect either.
Any ideas anyone?

Don't know if this will help anyone, but here goes. Suddenly, for no reason, I couldn't connect to Messenger for Mac with neither MY G5 iMac, or my MBP. I tried uninstalling MSN Messenger, removing Messenger .plists, even updating the firmware on my Netgear DG834GT. (I am no expert believe me).
In the router firewall list, it said all IM ports were open, and I re-set factory settings. All to no avail. Another odd thing, and I don't know if this is any way related, but when I tried to sign up to the microsoft for mac website, I could never seem to get a validation link sent to me, even though I had signed up, and clicked on send validation link..(They send you a link to click on to start the account). This meant that I couldn't even post questions about my problem.
In the end, I went a bought a new router, and hooray...problem solved. So whatever the problem is, it seems to be the router.