Apple has released iPhoto 7.1.1 [1], saying only that it "supports compatibility with Mac OS X 10.5, improves overall stability, and addresses a number of other minor issues." The update is available via Software Update as a 10.8 MB download; a standalone download [2] has also been posted. You must have already updated to iPhoto 7.1; if you've missed that version for some reason, install it first [3], and it in turn requires the iLife Support 8.1.1 update [4].
I'm in the final throes of updating my "iPhoto '08 for Mac OS X: Visual QuickStart Guide" book, and I'm looking forward to this 7.1.1 update's improved "overall stability." I haven't lost any data that I know of, but iPhoto 7.1 has crashed seven times on me so far while I've been writing in November.
If you ever want to see how unreliable an application has been, try this in Tiger (in Leopard, you can just look at the number of crash log files for the application in ~/Library/Logs/CrashReporter):
[1]: http://www.apple.com/ilife/iphoto/
[2]: http://www.apple.com/support/downloads/iphoto711.html
[3]: http://www.apple.com/support/downloads/iphoto71.html
[4]: http://www.apple.com/support/downloads/ilifesupport811.html