Store Mode

[cut-n-paste]

Do I need to totally re-install to update from 1.4.3 to 1.5.2 or is there some simple way to do this?

[raiwa]

You should uninstall the store module. Then upload and replace all files. Then install again the main module and customise the maintenance page.
Uninstall - reinstall is needed to update some configuration functions in the database.
Edit: you need to uninstall and reinstall also the header content message module for the same reason.