Consider the following scenario: 1) Install 7600 (original SP0) 2) Install Microsoft Virtual PC (KB958559/977206), build 7600 3) Install SP1, and the Virtual PC components are updated to 7601 So if you install SP1 onto an existing system that has VPC, both the core OS and VPC components are 7601. Now, consider this scenario: 1) Install 7601 (integrated SP1) 2) Integrated SP1 does not include Virtual PC, so install Virtual PC, but it's build 7600 3) ??? But if you install VPC after you install SP1 (e.g., if you use an integrated disc or if you install SP1 before installing VPC), you will get 7601 for the core OS, but the VPC components are still stuck at 7600. So... um, any chance that the leakers have a copy of the updated 7601 VPC?