I have downloaded "Goodnight.Pr2" into P01 and U01 on two different Proteus's. I played P01 on the first and U01 on the second at the same time. I also tried U01 on the first while running P01 on the second.
The lights and sound tracked without differences.

The code that runs Uxx and Pxx sessions is the same. It just goes to different memory locations for the session data. It may be possible that a bit didn't get programmed correctly or a memory location is faulty.

I'd try reprogramming the sessions, maybe adding sessions at the beginning so different memory locations will be used for the session in question.

In response to question #2 (in FirstA's first post) ...How the sound works?

If none of the check boxes... "Bin Beat", "Sound Mod" or "Dual B B" ...are checked then the Proteus will generate a continuous tone. The wave shape depends on which wave table option button is selected. Table1 is a sine wave, Table 2 is a triangular wave, Table 3 and 4 are complex wave forms made up of the programmed Pitch frequency plus some harmonics of the primary frequency.

Checking the Bin Beat box will make left ear run at the "Sound Pitch" rate and the rigth to run at the "Sound Pitch" rate plus the "LFO #1". So, if you had a pitch of 200 Hz and the red (LFO #1) was flashing at 10 Hz then the left ear would run at 200 Hz while the right ear would run at 210 Hz. Real Binaural Beats should use sine waves but they will run on any wave table. There is no modulation of the sound but if you listen to the two with headphones you perceive a 10 Hz beat.

Checking the "Sound Mod" box causes an amplitude modulation of the sound signal. There are many variations on the modulation. If the "Dual LFOs" box is unchecked then the sound will be modulated in time with LFO#1. A checked "Sync" box will cause the modulation to be in phase, an unchecked box cause the modulation of the left and right signals to be 180 degrees out of phase.

Checking the "Dual B B" box sets up a dual binaural beat. The first binaural beat is the same as a single BB. The second one is similar to the first binaural beat but will follow LFO#2. Also, the base frequency of the 2nd BB is a harmonic frequency of the "Pitch" frequency. This harmonic can be set using the "Edit Supplemental Commands" option under the "Utilities" menu. You can set the ratio of the base frequencies to 1/2, 2/3, 3/4, 4/3, 3/2 or 2.

As an example. Say your Pitch was set to 120 Hz, LFO#1 set to 8 Hz, LFO#2 set to 12 Hz and a BB2/BB1 ratio of 3/2 (1.5). Then in the left ear the base frequency for BB1 (120 Hz) will be generated along with the base frequency for BB2 (120 Hz * 1.5 = 180 Hz). In the right ear the binaural frequency for BB1 (120 Hz + 8 Hz = 128 Hz) and BB2 (180 Hz + 12 Hz = 192 Hz) will be generated.

You can use Sound Modulation along with the Binaural Beats but it kind of defeats the purpose of BBs.

One last thing that you can do with the sound is check the "Do Spcl Sound" box which sets a Special Sound Pitch. This value is also programmable using the "Edit Supplemental Commands" option. The frequency can be set to the nearest 1/10 Hz and does change during a segment. The check boxes, "Bin Beat", "Sound Mod" or "Dual B B" also work with "Do Spcl Sound".

Hope this explanation is of some help.

Best regards,
theRock