Missing tracks when exporting the whole mix

Hi there,
 
I've had this issue now way too often. I select all tracks of my mix and export. But on the mixdown Wave file one track is missing, sometimes it's two tracks or only parts of a track. When I hit play in Sonar everything is fine. No dropouts, CPU almost idle.
 
Tried 64bit engine on and off, tried, fast bounce on and off, PDC on and off.
 
I've had this on almost every track I tried to export, no matter which VSTis, Samples, Samplerate, or settings I used. This has taken so much time and caused so much frustration that I've given up on it completely now and instead record the mixdown on a separate track in Sonar where I set the input to "M-Audio Stereo Monitor". This works instantly, no missing audio.
 
Please track and fix this issue, I've been through a dozen of Forum post here about this problem since around 2005, none seemed to be resolved, people just joking if OP was maybe drunk or whatever. Please take this issue seriously, at least a handful of users seems to suffer from it. A DAW that can't mixdown is like a car that can't drive..
 
Thanks.
 
My system:
- Windows 7 SP1 64bit up to date
- Core i7 2700k, 16GB Ram, GTX 1080, SSD, Firecuda HDD, M-Audio Delta 44.
- All drivers up to date (well the latest M-Audio driver is from 2012)

Thanks, Dan.
 
Your way did work when I tried it. But it has a disadvantage for me, I cannot select a region to export. I'm making ambient tracks and more often than not I got very long drones, background noise etc. that have lot longer clips than the actual song.
 
With that option Sonar exports a lot more than the region I want, in fact it even exports minutes of silence only because there's an automation lane point going beyond the end of the song. Adjusting all of that.. man this could really be easier, and it's supposed to be.
 
EDIT: Sometimes you also have different clips "stored" beyond the end of the song, I've seen videos of professionals suggesting that workflow, although I'm not doing it.
 
So I have to stick with my original error report, this is a bug and should definitely be fixed. I can see no reason why the mixdown works the way you proposed it, but fails completed in any other attempt.
 

I dunno.... I usually do it exactly as you've described but haven't run into any missing pieces: Ctrl+A to select all, drag across the timeline, file > export audio.  I never have lanes open either, FWIW.