I have just installed MSN Messenger (live) for the first time on this new Vista 32 machine (all updates done). All the .Net files are there too, including updates.
As soon as the machine starts and MSN loads, Vistaghhhh!!!! does it's nut and reports a critical error, I should save any work, and it will shut down in one minute.
I managed to get Messenger out of the startup list, so the machine starts correctly.
But if I reload it, it causes the error once more.... and locks access to Control Panel too (thankfully I use Easycleaner, so use it's own method to stop Messenger loading at reboot).