I just updated to 10.5.2 this morning and encountered a bit of confusion (“Why the heck do I have to keep entering my password to delete a file?”) I tracked down the problem, discovering that the update, for whatever reason, changed the permission on my Documents directory to be read-only.

For those of you who find yourself in the same position, you can correct this from the Terminal with a quick:

chmod +w Documents

That’ll make the Documents directory writable again, and get your life back to normal.