We are running Svr 2008 R2 in native mode. the TFTP image is downloading in about 20 seconds which is fine.
The machine then prompts me to enter credentials. I do that and then I hit a problem, I have to wait upwards 10 minutes to get to the next screen (Task sequence selection).
I first thought this may have been a hardware issue, but this happens across multiple hardware types and machine types.