"render all" creates directories and unpredictable filenames

Hardware/Software
MacBook Pro
Retina, 15-inch, Early 2013
Processor 2.4 GHz Intel Core i7
Memory 16 GB 1600 MHz DDR3
Graphics Intel HD Graphics 4000 1024 MB
Software OS X 10.9.5 (13F34)

I’ve reproduced this several times with Reaper 4.76 and 4.75. Earlier versions don't have this bug.

When adding several projects to the render queue, and then selecting “render all”, the results are not the same as if you “render 1 file”. Instead, I’m getting a directory where I would expect each WAV file, and inside the directories are the rendered WAV files, but they are named unpredictably.

To reproduce:

I have two projects open in Reaper. Each is a ~45 minute live audio recording consisting of two tracks: a stereo track from audience microphones, and a stereo track from the soundboard. For the first set, I want to render it with the audience mics muted. For the second set, I want to render it both ways: with the audience mics and without. So I add three items to the render queue:
set 1, track 1 muted (soundboard only)
set 2, track 1 muted (soundboard only)
set 2, track 1 unmuted (soundboard + mics mix)

I gave each of these unique, descriptive names and used a directory called “Masters” for the destination.

The following listing is what I would expect to see this in the "Masters" directory (and this is what I do see correctly with 4.731):
Masters/2014-09-13 Hip Hatchet.wav
Masters/2014-09-13 Kevin Lee Florence sbd + mics.wav
Masters/2014-09-13 Kevin Lee Florence sbd ony.wav

Instead, I see this:
Masters/2014-09-13 Hip Hatchet.wav/qrender_141222_180944_2014-09-13 Kevin Lee Florence.wav
Masters/2014-09-13 Kevin Lee Florence sbd + mics.wav/qrender_141222_180959_2014-09-13 Kevin Lee Florence.wav
Masters/2014-09-13 Kevin Lee Florence sbd only.wav/untitled.wav

The WAV files are in the correct directories, but the names of the files don’t look right at all. “untitled.wav”? And “qrender_141222_180944_2014-09-13 Kevin Lee Florence.wav” is in the “Masters/2014-09-13 Hip Hatchet.wav” directory, which is not the same project.

If I use “render 1 file” it does exactly what I expect: create a file in the desired format at the location indicated. But rendering multiple files creates directories and carries names from previous projects to new renderings. This feature changed/broke in 4.75. I believe my only option currently is to use 4.731 until this is fixed.