I would re-register since there is always some sort of reprovisioning with it. The other side of the coin is to try it since at worst it wont hurt your situation any. I did the re-registering and have been all over with my phone for two days and have not had any roaming triangle show up at all.

P.S. Afterthought, so far everything that was at the site were we downloaded from has played exactly as they described it and they did point out the fact that you should re-register as one of the steps. The other point is what I have been saying all along the lower lever techs really are not quite sure what is going on and I would really not take what they say as facts.