Your host CAN NOT help you on this. It is IE that remembers "wrong" from the server move. Especially if you use IE7 with all those "anti-anything" filters.
Post a news announcement asking all users to clean their cookies related to your domain and restart the browser. After that they should be ok with a new login and "Remember" setting.
Well, then it might be relevant for all users to clear their browsers cache, since IE most likely got the info crossed somehow...cookies in particular. Do anyone have problwems logging in after the host change?
sorry I am not that good to change too much code. Everything was working fine until I changed to a new host a few days ago. I have just realised the people with IE can not see the highlighted new posts(the envelope goes yellow) but the people using firefox can.