The "Automatic" option for icon size under Tools>Options>LibreOffice>View uses OS settings, and would be the most sensible default option in order to integrate as well as possible with the system.
Overriding preferences by default that the user has already set in the underlying system is bad practice.
I agree. As far as I remember in Beta2 "Automatic" was default option?
*** Bug 30525 has been marked as a duplicate of this bug. ***
Fixed with commit 124c46e959a895a2008937a2ed71a9ffd25759e4 for libreoffice-3-3
Closing - Sophie