I would agree totally. I upgraded my N95 firmware a while back - and my pc hard drive made funny noises part way through - boy did I sweat!

If your pc or operating system is in any way unstable - i'd recommend against it..

If in doubt, use a pc that is known to be 100% stable (if there is such a thing!)

I was lucky, my upgrade completed succesfully - but I did panic a bit!