I just noticed that Pulseaudio's metadata.xml referred to two USE flags that are present in the 1.x series as restricted to version 9999 (which they were, at the time of introduction). The problem is that repoman does not throw an IUSE.invalid like it should at that point: if the USE is documented, but restricted, it should be considered invalid for the version it's not restricted to.
repoman support has been removed per bug 835013. Please file a new bug (or, I suppose, reopen this one) if you feel this check is still applicable to pkgcheck and doesn't already exist.