exchange 2010 users can't move or delete emails in owa

Hi

I have an SBS 2011 with exchange 2010 server

When my users are using OWa they can't delete or move emails

I have tried various things from the following threads

http://social.technet.microsoft.com/Forums/exchange/en-US/82327d84-ed7e-4865-8f4a-78378139f487/unable-to-delete-or-move-mails-in-exchange-2010-owa

http://social.technet.microsoft.com/Forums/exchange/en-US/fddc1483-c3f6-4dc6-b334-20707f87b2da/users-cant-delete-emails-and-other-tasks-in-owa-on-exchange-2010-sp2-ru4

Done some more research and still no use

issue is still there even accessing OWA from server itself

does anyone know anything else that can fix this problem

thanks in advanced