Error upgrading from MetaFrame Presentation server 3.0 to 4.0

Hi folks,
I am having a problem upgrading MetaFrame presentation 3.0 to 4.0 for Microsoft windows 2003 server.
It starts out just fine, but halfway through the upgrade process I get the following error;

Installer Information
Error 10001. Installation of MetaFrame Presentation Server failed.
Do you want to continue with the installation of the next component?
I am upgrading on a system where Multilingual user interface (MUI) is installed. MetaFrame presentation 3.0 was already installed when I installed (MUI). So am wondering if (MUI) could be the reason behind the error and if not what is the problem with my installation?
I have visited Citrix support site, but I don’t seem to get a solution to my problem. I will really appreciate any help.
Thanks.
