I always export my setting before doing either an update or clean install. The last thing I want is to start from scratch again.
The only reason I'm forced to do a clean install is the update fails to take a blind bit of notice of my existing configuration (no web control or anti-spyware installed) and even worse my wished in the actual update install. It installs modules that weren't previously installed, albeit disabled, but as I said I don't want it disabled, I don't sodding want it installed, that really does pi** me off.
Its a great firewall; my gripe is the pi** poor installation not honouring my wishes/settings, the total lack of an update from the GUI, so only the components installed get updated. Having to download the complete installation file for every update however minor (like this one 0.0.1 increment) and an update that doesn't actually update but installs components you got rid of.
All of the above forces me to do a clean install, having exported my configurations and importing them into the new install, this has worked without problem in the past. This time round importing the 7.5 settings for some reason completely breaks 7.5.1 causing a BSOD on the next boot after importing on my win7 SP1 netbook. But no such problem in doing that on this XP Pro SP3 system.