When starting SQL Server 2005 Management Studio, I regularly (at least once a week) get a warning message box (yellow triangle) containing the above error message. If I click on it, I get another message box, this time an error(red circle, white cross) with the same message. If I click that, the program exits. It is not possible to recover from this error without rebooting - subsequent restarts of the software result in the same behaviour. No hint is given as to where to look for error messages or possible resolutions, nor is the option given to report the problem to yourselves.
On examining the System Event Log, I see a series of DCOM errors relating to SQL Servers I have set up that I normally access over a VPN link. These errors occur only once, corresponding to the first time I tried to start SQL Management Studio this morning. The errors are all as follows:
"DCOM was unable to communicate with the computer XXXXXX using any of the configured protocols".
(Where XXXXXX is the name of a server normally accessed over VPN).
Simply starting the management studio should not try to connect to these machines - the connection should be initiated at my request unless I instruct it otherwise; either way it should not cause the software to exit.