Having problems moving frm API 1.0 to 1.1


ok, we so have had a Silverlight in Browser application that used to use API 1.0 to get Home and Profile Timeline
we have reprogrammed for API 1.1 using api.twitter.com/1.1/statuses/user_timeline.json & api.twitter.com/1.1/statuses/home_timeline.json

we have less than 200 users simultaneously but are constantly getting error 420 after a few minutes

Whats the best practice for a company like us?
We have two hundred users. they just need real time access for their tweets (home and profile) and to be able to do status updates.


Wow, no answer after 11 days.
we have applied for beta site stream access, no answer from twitter.