Princeton University's Office of Information Technology is now suggesting that the iPad's DHCP lease renewal problem may be related to the iPad's screen being locked, either manually or automatically. The best workaround seems to be to disable automatic screen locking and avoid locking the screen manually; the downside to this is of course reduced battery life. Other (but worse) possibilities include turning off Wi-Fi or the entire iPad at the end of each session.follow link
Go Back and Forth Fast in Preview
If you're reading a PDF in Apple's Preview software, and you follow a bookmark or an internal link to move around within the PDF, you can quickly return to where you were by pressing the keyboard shortcut Command-[ (that's Command-Left Bracket). Or, you can choose Go > Back.
The command works iteratively, so you can go back to just the previously viewed page or if you issue the command again, to the page before that, and so on. There's also an equivalent Go > Forward (Command-]).
- ExtraBITS for 3 May 2010 (03 May 10)
Princeton Suggests Workaround for iPad DHCP Flaw