Q: error -3259 showing when I try and upgrade iphone software

Hey antoinew1,

I found an article that goes over that error within iTunes - not sure if that is where you're seeing it, but if so, check out the following troubleshooting steps:

Resolution

1. Remove any proxy information you have set up.
2. Update to the latest iTunes software version.
3. Try turning off your Firewall to see if the issue is resolved (this includes the built-in Firewall or a third-party Firewall such as Norton Personal Firewall, McAfee, Symantec, etc.). Learn how to turn off your Firewall:
   • Steps for Windows.
   • Steps for Mac OS X.

via:

iTunes Store reporting error - 3259

http://support.apple.com/kb/ts2799

Take care,

David