I've been building a VPC which includes MS Commerce Server 2007 as one of the components, and I ran into a bit of an issue today. I tried to install the Business User applications and got the following error:
Microsoft Commerce Server 2007 Business User Applications requires version 6.0.3724.0 of Microsoft Commerce Server 2007 Client Tools. Please uninstall any other version of the Client Tools and retry.
It didn't take me too long to figure out that this was because I had already installed SP1, and SP1 upgrades the client tools component. Lesson to learn here: Don't install SP1 until AFTER you've installed the Business User apps.
It seems that uninstalling SP1, installing the BU apps and re-installing SP1 seems to fix my issue for now.