Over at the ConfigMgr Support Team Blog, interesting write-up on failure encountered when using the ConfigMgr Service Manager to connect to Secondary Site servers ...
Here's a unique issue I came across the other day that I thought you might like hearing about. In this case, we were unable to connect to a ConfigMgr 2007 Secondary Site server from Tools => Service Manager unless we were using a domain admin account.
When attempting to connect to the Secondary Site server in Service Manager we received the following error message:
ConfigMgr Service Manager
Error communicating with the specified ConfigMgr Site Server
This error can occur if the SMS Groups do not contain the proper Site Server computer accounts.
You may also receive the following error when attempting to connect to the Secondary Site server in Service Manager if the logged on account is not a member of the Secondary Site Server's Local Administrators group:
Access to the specified server has been denied. You might not have enough security rights to complete this operation
SMS Group membership and/or Local Administrator group membership configuration is not configured correctly.