Broken Flash uploads in OS X Leopard
Adobe has acknowledged the problem and promises that a fix is forthcoming (though the date of such fix is unknown), but this still leaves many users in a lurch.
As far as we know, the only partial workaround that exists is to put the Flash 8 Universal Preview Beta plugin in the ~/Library/Internet Plug-ins folder (renaming the existing Flash plug-in, if it exists, and also renaming the flashplayer.xpt file) - but users should be cautioned that this pseudo-solution is EXTREMELY UNSTABLE. After experiencing frequent browser crashes and kernel panics, we stopped using the old plug-in - even in a separate user account - because the trade-off just wasn't worth the ensuing hassle.
We'll keep you updated on any patches or new workarounds as they develop.
Update: Adobe has released an update that fixes the issue. This is a release candidate prerelease, so you may still find a few bugs, but at least you can upload all of your embarrassing Halloween pictures to Flickr en masse.