WinSP gameplay question + tech question.

[General SP]

Just setting up another game that involves lots of wooded hexs and a thought just occurred to me, does WinSP model airbursts of arty fire in trees and if so by how much does the damage caused ramp up ? In other words is infantry safer from arty in wooded hexs or clear hexs ?

Also i currently have MBT installed and patched up to the latest but i want to have another install using an older patch version, whats the best way to do this without corrupting the current games i have going at the moment ?

Easiest way to install an older version:
When it displays the pathway to install change it to something else such as:
C:\SPMBTversion20 and lets it install. If you are applying patches to this install also then you will need to browse to the new directory of course to install them. Next go to your desk top and right click and create a new shortcut to the new directory launch. Hope that helps :)