Samsung Galaxy S :: GPS Not Turn On Despite Maps Or Navigation Being Chosen

i know there are problems with the GPS on this phone. I have read loads of posts and tried changing various settings but am pinning my hopes on Froyo fixing it or else i will seriously be looking at returning phone as not fit for purpose. I am sorry but i feel that having paid ?380 for something advertised as having GPS, maps, navigation etc that i should be able to have this in a usable fashion. I dont want to be told its a phone, sat nav is a bonus. It was advertised and sold as having sat nav and this should be workable. OK sorry rant over, just trying to head off some of the comments i am sure will be posted, anyway back to the problem.

when i start maps or navigation it shows a small radar looking icon in top left hand corner, indicating it is looking for satellites, yet at other times this does not appear and it shows "Searching for GPS" at bottom of screen. The manual states this icon means GPS activated. When it is not showing does this mean that the GPS has not turned on despite maps or Navigation being chosen. I can drive about for an hour with this message showing but navigation not starting. The strange thing is if i have map on the screen it will show my location moving yet still say searching for GPS, if thats the case then how can it update maps, how does it know where i am. I an really annoyed at the lack of this function (can you tell). Thanks for any insight into this.