I have installed v6.1 on XP SP2, and it works OK. Siemens doesnt recommend it though.
I have heard that there should be an installation program deeper within the directory structure of the CD for v6.2 that will run without checking for XP SP2.
Also, there should be a Windows setting somewhere to trick the installation program so that it thinks it is running on a previous version of Windows. Havent tried it though.