You need three satellites for a 2d fix and 4 satellites for a 3d fix (height above sea level). If you have 5 satellites fixed out of any number then you're well okay. Seriously, I would fix the broken stuff first rather than looking for a problem that might not exist. Get it coded forst and see where you're at then. If you're still having issues then you can try another gps antenna, but until then I'd get someone to code it in for you first.