IE keeps prompt for password for IIS website

I have an IIS website hosting reporting service and I use integrated windows authentication.
The problem was my IE keeps prompt for password while I can log in successfully using firefox.
I am using IIS 6.0, IE 6.0. After googling I got this trick :
Go to Tools > Internet Option > Advance > Untick 'Enable Windows Integrated Authentication'.

Dynamics AX 2009 reporting service error

I used to get this error message when opening reporting service from Ax :
Error during processing of ‘AX_CompanyName’ report parameter.
(rsReportParameterProcessingError).
Even this error occured in the AX 2009 VPC that previously works perfectly.

This information from partnersource (requires partnersource login) says that in SQL Server 2005 the execution account should not be used, and in SQL Server 2008 it is set to BC proxy account.
I am using SQL Server 2005, so I clear the execution account in the SSRS configuration (Start > Program > SQL Server 2005 > Configuration tools > Reporting Services configuration. In the execution account part (the bottom one), clear the option 'specify an execution account'.

Hope this helps many people trying to solve the same error message.

Configuring reporting service for Dynamic Ax 2009

I follow the steps in Ax installation guide on how to install reporting service for Ax.
When I came on setting up application pool, I got this error

The identity of application pool 'AxReportServer' is invalid, so the World Wide Web Publishing Service can not create a worker process to serve the application pool. Therefore, the application pool has been disabled.
This is corrected by assigning Ax proxy account to local IIS_WPG user group.

Later I need to assign ax proxy account to ReportServer and ReportServerTempdb database.