On installing iLife ’11 on a new install of Mountain Lion I found that iPhoto won’t run. It advises to check for updates which don’t come up in Software Updates.
The solution is to download 2 updates from Apple’s site.
iPhoto 9.3 Update (requires iPhoto 9.1)
After downloading and installing these iPhoto runs. Additionally, now when running software updates a new update for iPhoto 9.3.1 appears