I am currently working on H1-B (9th year) and my existing H1-B is uptil Jan 2012. I am planning to change job roles INTERNALLY within my current company next month and this will need amending my H1-b. Please clarify:
1)Is it safer to file the amendment and wait for it's approval, before changing job role? if their is no decision on the h1-b amendment request, before the listed start date in the amendment, should i still move to the new role on that new date?

2)In case there is any RFE (or denial in the worst case) for the amendment request, will it impact my existing status of H1-B? Can i still continue in my current role till Jan 2012?

Please clarify the safest way to proceed with this h1b amendment. CHange of roles is INTERNAL to the company and is same location.