Hi, same problem here. I tried the Option start, new library, but it crashes straight thereafter, and then I can't even do a new option-start on it anymore for several attempts. I just get the "iPhoto quit unexpectedly" and then I click reopen I get "The last time you started iPhoto it unexpectedly quit. Do you want to reopen your windows" prompt. Clicking reopen doesn't work. iPhoto just sits there, doing nothing.
How do I uninstall it and reinstall it from scratch? I moved it to Trash, but when I go into the App Store, iPhoto is listed as £10.xx, and surely I'm not expected to pay for it when I already had it?!
(Option-Cmd open doesn't work, same quit behaviour as above)
(Option open sometimes works, but even if I select New Library, it just crashes straight after that).
Only happened since going to 9.4.2. Didn't happen on 9.4.1.
Secondly, I see nothing in these issues that suggests that iPhoto is the problem. Odd cache problems (in one case on this thread) damaged libraries, data related issues cannot be fixed by the app.
Update: turns out my iPhoto crashing was just the first symptom of a failing hdd. Eventually everything started failing, and had to get my hdd replaced. Apple did so without charge even though I'm outside my 1 year warrantee. They also replaced my iMac's screen as it had some ghosting issues -- again, without charge. Excellent service. I then timemachine'd my backup back, and am fully up & running again.
My situation is the same as Seekoei. My computer had a damaged HD and it had to be replaced. I have timemachine, so I shall have no problems. People from apple repair store told me that there is a recall on some iMac for damaged HD, notwithstanding my one is from the period covered (mid 2009) my serial number is not covered.