I was able to fix the problem by restarting my computer, but I wanted to see if anyone else had this issue.
If I right click on a keychain item and select "Copy Password to Clipboard" the usual password confirmation dialog box didn't come up and the password isn't copied.
If I press ⌘+i and check the "Show Password" box, the confirmation dialog box does not show up and the check disappears after a fraction of a second.
I also tried locking the login keychain thinking that maybe if I locked and unlocked it the behavior would be fixed. But clicking the lock in the top left corner does nothing.
Like I said, restarting fixed the issue.
So this is happening again about a month later.
I opened console and there is nothing logged under "All Messages" when I click the "Show Password:" checkbox.
When trying to copy an application password rather than a web form I get: "Access to this item is restricted (-25320)"
Keychain first aid says there is nothing wrong with the keychain.