This is one of the major issue i had and striggugeled for long time....here it goes
When i connect SharePoint calender to outlook i am able to get the events/tasks/items from Sharepoint to Outlook Calender but its not happening viceversa..such an idiatic issue we got ever..
This is a very simple solution you jus need to remove the redirects from the IIS i.e. you just need to uncheck the redirects from the IIS
Window(button)+Run-->type inetmgr-->go to redirected site-->check the redirects icons-->uncheck if any redirects are given if so remove them.