i have strange issue users syncing with imap reported that only new messages are in order then the inbox shows the last email in inbox for example

imap folders look like

1- email from 18/6/2010
2- email from 18/6/2010
3- email from 30/12/2007
please note that the email from 30/12/2007 is the last email in the inbox folder

i tryied to rebuilt the inbox but it start saying starting index but there is no progress or any thing

though all services are working fine

if index was the solution to sync time stamps how can i reindex all users