Theses are symptoms of leaking fuel injectors. But it could also be DME software related. If you are still under 80K miles, the repair should be covered under the FED emissions warranty. There was a Software error in the DME that causes hard starting after vehicle heat soak for early X5 N62 Engines. The bullitin no longer exists in the BMW online database. You must ask the dealer as they may not be familar with the bullitin. If the DME software is up to date, remove the fuel rail, and check the injectors for leaks.