I had a problem with connecting my ipad to my VPN, I was getting authentication problems or connection problems, after searching for a couple of hours with no hint of a solution I came across a reference to a tip offered by an Apple tech which was to reset network settings and what do you know it worked! I guess network settings are corrupted now and again or the upgrade to 4.2 and the jailbreak broke something . It requires a reboot so beware tethered jailbreakers. You'll also have to re-enter all your network settings including WiFi keys. Simply go to General and select the reset menu :
Then select reset network settings from the next menu :
The ipad should then reboot.
