Portfolio Server 2007 Reporting Error

[am_yousef]

I have a server for Microsoft EPM Solution (Windows SharePoint Services,
Project Server and Portfolio Server 2007), and other server for SQL Server
2005

The EPM 2007 Server has the following software Installed:

1. Windows Server 2003 Service Pack2
2. Microsoft .NET Framework 2.0 and 3.0
3. Windows Internet Explorer 7
4. Adobe Reader Version 9
5. Microsoft Office Excel, Word, and Visio 2007
6. Microsoft Office 2003 Web Components
7. Microsoft Office Project Portfolio Server 2007 Service Pack 1
8. Microsoft Office Project Server 2007
9. Microsoft Office Project Professional 2007
10. 2007 Microsoft Office System Servers Service Pack 1
11. Microsoft Windows SharePoint Services 3.0 Service Pack 1

The SQL Server 2005 Service Pack 2 has the following SQL Components:

1. SQL Server Database Services
2. SQL Server Integration Services
3. SQL Server Reporting Services
4. SQL Server Notification Services
5. SQL Server Analysis Services

When i try to add a new report in Project Portfolio Server 2007 through the
following steps:

1. Click on the reports link in the Project Portfolio Server 2007
2. In the "Add Report" Page, select a "Report Template" and click "New"
3. Enter the "Report Name", and select the "Project Attributes" that will be
shown in the report
4. Click the "Save New Report" or "Run Report (PDF)" button, and the
following error message will appear.

The permissions granted to user 'domainname\machinename$' are insufficient
for performing this operation. More Info:
http://go.microsoft.com/fwlink/?Lin...erver Reporting Services&ProdVer=9.00.4035.00

I would appreciate any help as this issue is very urgent.
Thanks.