I don't recall you can actually set that anywhere, I suppose you mean your projects are 48K/16?
Mine are 44.1k/24 btw.

I shall wait for said results (off to bed now, UK time)

I'm rendering the OMF now...Hey NICE TRACK by the way!!!
I'll see if I get an error report

Yep, I got the error ...
 
I'm going to try "bouncing to clips" and then try it again.

I recall eventuall beimg able to export but the steps pretty much was mpre work than exporting stems

OK..Done.  643 MBs.   I succefully exported an OMF.  It took 3 tries.
 
I was working fast --so i did things without worring about concequences, Here is what i did.
 
1) Deleted the track "quad-capture".  That seemed to be just a mix of the song, but it probably could have stayed.
2) Deleted all soft synths--again probably uneccesary.
3) Opened up all folders, started "Bouncing To Clips" eveything.  I could not grab everything at once, so I grabbed as many tracks as I could at a time to bounce to clips.  This is proably very important.  every clip that overlaps with another generates a new track in an OMF.  Having so many clips and tracks becomes overwhelming to organize, and probably too much for the system to handle.
4) After all tracks had all the clips "bounced" so no clips where overlapping any more. I went to "Process Audio>Remove Silence".  This removes all automation, so I suggest experimenting with this.  You might want to "Freeze" all your audio tracks 1st.  That will print any fades or effects.
 
Anyway if you'd like the OMF..PM me and I will DropBox it to you.
 
I'm guessing the issue people are having with OMFs are too many clips that overlap on a track. Also track automation might be getting in the way. 
 
  

It did not really take me very long,  I had a lot of interruptions.  Like take my daughter to a Flute lesson, eat dinner and run to the store. 
 
all in all about 20 minutes

Thanks Jimbo.  I will play around with this again

Thanks a bunch for your efforts, I will give this a try tomorrow and let you know!