VideoStudio :: Lower Left Channel Volume In Stereo Down-mix Stream?

I am using Corel Video Studio Pro x4 Ultimate with SP2 and I getting significantly lower audio volume in left channel for all stereo downmix streams. The problem is consistent regardless if I make an AVCHD video with background music, or create slide show form still images with music.

I want to eliminate any possible PC setup or installation issues and narrow down the problem to program itself. I have attached sample of stereo 1 KHz 0db test tone, which could be used for this test.

1. Open new project
2. Choose Settings --> Enable 5.1 Surround sound and Wide screen 16:9
3. Import to the library few pictures and 1KHz 0dB.wav
4. Place on the time line pictures (I used 5 sec duration for display and 1 sec cross-fade transition)
5. Add 1 KHz 0 dB.wav to the Music track
6. Select Share tab --> Create Video file --> Custom
7. Choose MPEG Transport Stream .m2ts
8. Select Options --> General 1920x1080 --> 29pfs --> upper field first
9 Select Compression --> Quality 100% --> Dolby Digital Audio --> 3/2 (L,C,R,SL, RL) --> 448 kbps --> OK
4. Name the file and save it.
5. Play rendered file on 2 speaker system (TV or PC)

Playing 5.1 surround sound movies on 2 speaker (i.e. stereo) system will likely force to play Stereo downmix stream only from 5.1 sound. You then should be able to observe that the left channel volume is reduced by -14 dB. (at least this is what I get) which causes significant stereo balance shift.The same test can be done with music files, but if you want to measure the volume drop, test tone is the best way to quantify it.