A way to get GPS to work
I have managed to get GPS signal in less that 20 seconds in my Galaxy i5800 (original firmware I5800XWJG8), here is what I do.
CAUTION: USE this ONLY if you have a 3G data plan enabled from your provider! otherwise you provider will charge you in your monthly bill
1. Turn on mobile data (I use Quick Settings app found in Market that makes it easy to select-deselect)
2. Turn on Auto Sync Data (Settings/Accounts and Sync or more easily using Quick Settings app)
3. Turn on GPS
4. Run GPSopt app (You can find it in Market if you type in search "octy", it is the app named GPS Optimisation, download it and install it first)
5. Run your navigation app (I use nDrive)
-I pass steps 1,2 cause I have them always enabled (I makes battery last a little bit less though).
-You can pass step 3 also as you can set GPS always on without battery draining since GPS is used only when the navigation app asks for it.
-You can make easier the whole procedure if you use another app named Tasker and make a profile that automatically after you run ndrive, tasker runs gpsopt first.
Hope I helped until Samsung corrects the GPS bug.