I have the same problem on a few client machines. I've figured out that this error occurs when I run the second instance of SmartSpace.exe.
When I click "Install the Smart Space Client" (http://myserver:17080/SmartSpace/SmartSpace.application) the installation window appears and I click Install. After download is completed SmartSpace.exe seems to be running because it exists in processes list in Task Manager and is using 2-3% CPU. There is neither Logs directory nor SmartSpace.log file under C:\Documents and Settings\user\Local Settings\Apps\2.0 folder. I've also noticed that there is no Oracle Smart Space shortcut on desktop but only in Start Menu\Programs\Oracle Smart Space, Fusion Edition.
When I click "Install the Smart Space Client" again or run Smart Space Client from Start Menu the second instance of SmartSpace.exe appears in the processes list and after few seconds "Failed to connect to an IPC Port" message is shown and is written to SmartSpace.log file under C:\Documents and Settings\user\Local Settings\Apps\2.0 folder. After I close the message the first instance of SmartSpace.exe still exists.
From now on the situation repeats: every time I run "Smart Space Client" for the first time the process stops after a few seconds and when I execute it again it shows "Failed to connect to an IPC Port" error.
System configuration: MS Windows XP Professional SP2, IE 7.0, .NET 1.1, .NET 2.0, .NET 3.0
I've tried to install Smart Space Client on the server machine with the same result.
So far I've installed successfuly Smart Space Client on one client machine but I haven't noticed significant differences in OS configuration between other client machines.
This issue occurs when the Smart SPace client is installed in a localized (non-English) version of Windows.
The resolution is the following workaround:
1. Create a local group in your Windows client named "Everyone" (using Engligh characters) and include
your localized version of the "Everyone" group (whatever it is called in your
installed operating system language) to this newly created group.
2. Restart Smart Space, verify the Smart Space client starts-up correctly and
then check to esnure the Windows Explorer integration is working after connecting to
Hyperion BI, Oracle BI and/or Oracle BI Publisher