I've read that this is the new code: *#3214789650#

You can also make a handy-dandy shortcut for this:

Add a shortcut. Pick Activities. Find LbsTestMode. Then pick com.sec.android.app.lbstestmode.LbsTestMode.

Or, pick up this app:

SGS Tools - Android app on AppBrain

It has a number of useful shortcuts.

 

I had also modified my GPS settings prior to the update, and the update did not set them back to default, so you need to use the number posted above and get everything set back to the original defaults. At least the default settings have worked best for me.

When you say it's stuck "search for GPS" do you mean in Google Navigation? If so, that's a known problem. It's been submitted to Google on their Nav forum for several different brands of phones, so it's not just a Vibrant issue.

If that is what you are referring to then the workaround is to use one of the GPS Test apps and get a good lock, then go into Google Nav and it should get a lock quickly. I've also had better luck waiting on the first Google Nav screen until the sat disk icon in the notification bar shows it's locked before entering my destination.

If you really want an instant lock in Maps or the navigation apps then use the version of GPSTest written by Mike Lockwood (it's in the Market). When you run it you have to press the Menu button and select Start. Once it gets a good lock with at least 4 sats with the "U" flag, then press the Home key. This will exit the app, but leave it running in the background and GPS locked. You can then go into any other GPS app and the lock is instantaneous. No "Searching for GPS".