Ok so i ran the ABX test with the pretzel logic files three times: Replaygained individually, Replaygained as 1 album, and without. The results were easily recognizable. So there indeed seems to have been some processing and/or a level mismatch.
foo_abx 1.3.4 report
foobar2000 v1.2.4
2013/04/02 13:06:04
File A: Z:\Downloads\testSounds\foobaroutput.wav
File B: Z:\Downloads\testSounds\jplayoutput.wav
13:06:04 : Test started.
13:07:13 : 01/01 50.0%
13:07:29 : 02/02 25.0%
13:07:41 : 02/03 50.0%
13:08:21 : 03/04 31.3%
13:08:54 : 04/05 18.8%
13:09:21 : 05/06 10.9%
13:09:37 : 06/07 6.3%
13:09:54 : 07/08 3.5%
13:10:10 : Test finished.
----------
Total: 7/8 (3.5%)
foo_abx 1.3.4 report
foobar2000 v1.2.4
2013/04/02 13:11:26
File A: Z:\Downloads\testSounds\foobaroutput.wav
File B: Z:\Downloads\testSounds\jplayoutput.wav
13:11:26 : Test started.
13:11:45 : 01/01 50.0%
13:11:56 : 02/02 25.0%
13:12:07 : 03/03 12.5%
13:12:15 : 04/04 6.3%
13:12:24 : 05/05 3.1%
13:12:35 : 06/06 1.6%
13:12:50 : 07/07 0.8%
13:13:03 : 08/08 0.4%
13:13:08 : Test finished.
----------
Total: 8/8 (0.4%)
foo_abx 1.3.4 report
foobar2000 v1.2.4
2013/04/02 13:14:07
File A: Z:\Downloads\testSounds\foobaroutput.wav
File B: Z:\Downloads\testSounds\jplayoutput.wav
13:14:07 : Test started.
13:14:22 : 01/01 50.0%
13:14:31 : 02/02 25.0%
13:14:39 : 03/03 12.5%
13:14:45 : 04/04 6.3%
13:14:58 : 05/05 3.1%
13:15:06 : 06/06 1.6%
13:15:17 : 07/07 0.8%
13:15:26 : 08/08 0.4%
13:15:28 : Test finished.
----------
Total: 8/8 (0.4%)