Event ID : 1031

Issue: One of the System Attendant's task is blocked.

Event Source: MSExchangeSA

Cause :This problem occurs if the RootVer registry value is invalid.
This problem may also occur in the following scenarios:
1. When you remove Active Directory from the domain controller, the ASPNET security account is removed. Therefore, the metabase update service may not be able to start. Additionally, several events that are mentioned in the "Symptoms" section may be logged in the Application log. To resolve this problem, reinstall Exchange Server 2003.
2. When there is a permissions issue, several events that are mentioned in the "Symptoms" section may be logged in the Application log. To resolve this problem, run the Exchange Server 2003 Setup program by using the /domainprep switch, as in the following example:
drive:\setup\i386\setup /domainprep

Description : One of the System Attendant's task is blocked.This problem occurs if the RootVer registry value is invalid.

Action Required :
If the computer is running the Microsoft .NET Framework 1.1, set the RootVer registry value to 1.1.4322.0. To do this, follow these steps:
1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ASP.NET
3. Double-click the RootVer value, type 1.1.4322.0 in the Value data box, and then click OK.
4. Quit Registry Editor.

Ref.Link : http://support.microsoft.com/kb/906154/en-us