I am attempting to install the WebSphere MQ v6.0 Trial software, but can not get the "Prepare WebSphere MQ" Wizard to complete. The error message that I keep getting is "an unexpected error occurred while validating the security credentials for \websphere". I am installing on a Windows 2003 server and I have a Windows 2000 domain controller. I am logging onto the server with the special domain account that was created following the setup instructions (\websphere). I have tried the following:

1. Downloaded Trial software
2. Installed prerequisite software (items show as "OK" in the Launchpad)
3. Created domain userid (websphere) and domain group called "domain mqm", per setup instructions. We have even gone as far as making the "websphere" userid a Domain Admin.
4. In the "Launchpad", under "Network Configuration", selected "Yes"
5. Performed WebSphere MQ Installation; selected "Custom" and changed the install directory from C: to E: (left the rest of the install directory as it defaulted)
6. Attempted to run the "Prepare WebSphere MQ" Wizard. The Wizard creates the local "mqm" group, the "MUSR_MQADMIN" local account, adds the domain "domain mqm" group to the local "mqm" group, and adds the "MUSR_MQADMIN" account to the local "mqm" group. I have added the "MUSR_MQADMIN" account to the local "Administrators" group. Wizard fails because of an error while "validating security credentials for \websphere..."

The log excerpt below is the only place that I see a failure in the log:
CheckSecurity: Checking that the MQSeries Services can read the group membership of the logged on user
Retrieved token information
Retrieving group memberships for curren user \websphere
CheckGroups return code 1722 (0x6ba)
CheckSecurity: rc=2 (0x2)
Checking Services status: SECURITY_STATE_UNKNOWN