>If a server crashes while transacting with the client, does not the client loose it's instance?

I guess no. Need to test it, but the purpose of DCOM was to organize stateless working with COM objects without being aware about Internet (thing client) disconnecting to make it more reliable (compare to the working with SQL Server through internet that is much less reliable just because maintaining connection with SQL Server takes a lot of time when working thruogh through internet and internet disconnecting causes losing connection session to SQL Server).