With the release of iOS 4.3.5 and 4.3.10 earlier today, I think it would be safe to remind you to stay away from the “update” button if you care about your jailbreak or unlock.
If you run a stock iPhone or iPad then go ahead and update to the latest firmware. But if, like most iDB readers, you heavily rely on a jailbreak/unlock, make sure you do not update…
You’d still be able to jailbreak iOS 4.3.5 using RedSn0w, but it would be a tethered jailbreak, meaning you would have to plug your iDevice in your computer to tether boot it every time you have to start it up.
Updating to the latest firmware would definitely make you lose your software unlock no matter what.