Jan Kotas, a developer on the CLR team, and an original member of the Rotor team has recently started a servicing project for the V1 source. This fixes a few known issues, and for the interest of google indexing, fixes one issue in particular that many will eventually run into: Windows XP SP2 Rotor build bug. It also includes fixes to support the building and running of Rotor V1 on the following OS's:

- Windows Server 2003
- Mac OSX 10.3
- FreeBSD 5.2
- Windows XP SP2

Follow this link for more details. While you're at it, jump on the list too!