Email Reply all problem

Hi All,
I just bought N900, basically it is a very good HP with few features. but i have problem when using email exchange. Receipt adn send email is working normally. Problem is come when i want to reply all an email with more than 3 'To' (recipients), in the 'To' windows only included 2 recipients instead of all recipients on original email.
It is important for me. Any body here know how to resolve this problem?

Regards,
Iswahyudi.