Hi
I can confirm that one installation that was stuck on 2600 did upgrade OK to this new version.
On a PC that I had tried using the manual uninstall command line, and couldn't previously get an install to run, did install this OK, but it did think that a previous version had just been uninstalled and wanted to reboot (even though it was uninstalled days ago and this was a fresh boot).
Both PCs were XP Pro SP3
Where does the issue lie, and what are the next steps?