iPhoto bug: There is not enough disk space to complete that operation.
iphoto 4 has many, many bugs. One of the odder sets of bugs appear to relate to math overflow bugs (divide-by-zero type) which manifest as either absurd image sizes or boundary errors. These bugs often manifest with a single cryptic error message:
"There is not enough disk space to complete that operation"
Sometimes this bug appears because iPhoto has internally calculated an absurdly large image size. The image size in the file system is normal, but iPhoto displays the overflow state for a LARGE_UNSIGNED_DECIMAL: 175921860444.
The best workaround for this bug is to crop the image, then revert to original. iPhoto moves the image to the "original" folder, then moves it back to the standard folder, and thus recalculates sizes. (An AppleScript to detect these images and do this across a library would be handy.)
A related bug occurs at the 4GB free on drive boundary. (It may occur at other drive sizes too). The workaround is to duplicate some data so the free space on the drive is LESS than the boundary condition. Here's how I demonstrated that.
When I first experienced the bug I had about 4.3 GB free and I was unable to export 870MB of images. I restarted my iBook, which had the side effect of freeing up 1GB of space (caches?). So I went fom 4GB free to 5GB.
I was then able to export the images.
I then had about 4.26 GB available. I then got the error message when attempting to export the same image set, but was able to export a smaller subset. I continued on the same vein, reexporting the subsets again and again, getting the error message and then exporting a smaller set. Finally I got to the point that a single image export triggered the error message.
At that point, I had EXACTLY 4GB free on my drive. I then DUPLICATED a folder of images, so I had 3.89 GB available.
I was then able to export again.
So the workaround for this bug is to duplicate a large folder and cross the remaining size boundary, then recommence the export.
If Microsoft released a product like iPhoto 4 they'd be pilloried. I use (with deep regret) many, many Microsoft products under Windows XP, and I've never experienced anything as buggy as iPhoto 4. The only comparison I can make is to some versions of Quicken.
I think we've been too forgiving of Apple. I realize they don't have the money to do internal QA. They can, however, adopt the open source approach to public betas. They can charge for the release version.