Disclaimer: this bug has been filed in a semi-automated manner. When emerging the package kde-base/dolphin-4.8.5, the following elog messages are displayed: * For .exe file preview support, install media-gfx/icoutils. Such messages should only be displayed when the package is a new install. These situations can be checked in the ebuild as follows: if ! has_version 'kde-base/dolphin'; then See the tracker bug 440214 for more details.
Once again, what does this have to do with whether there is a previous version?
As in bug 440486, I think that even though the message is still valid, the user is interested in such an information when the package is installed, but IMHO it's not interesting for the user after an upgrade.