Comment 29 for bug 528094

One further detail about this that I didn't notice until now: When running the dbus-send command, I get a DBus error as follows:

Error org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Since I'm not knowledgeable on DBus I wouldn't know how to repair this, but judging from other forum posts dealing with this same type of error it seems like it's more of an ignorable warning rather than a serious error -- as a matter of fact, the screen locks correctly. Maybe there is some other finer point to making this session lock tweak without error that I'm missing?