public folder not visible in outlook 2010 -ExhServer 2010

Hi

I  have Exch Server 2010 with  SP2  working fine without any issues.

Now I create Public Folder and under that I create a SubFolder for Sales.. and give Owner ,Contribuet , Auther Permission to few user..

1.They are able to see only Public Folder  from OWA  but cannot access it--"0utlook web app cannot open public folders "

2.From Outlook 2010 I am not able see any Public folder atleast from OWA I can see but could not open due to above error.

Tried restring RPC Server and also tried  addeding diffrent permision nothing worked.

Can some help me with problem ?

Regards

Shiva

shivakumarmv