X3c 64bit Engine Export

Hi all, i just had another great day working with X3c. 
 
However, towards the end of the day, i exported the project using an previous profile i saved while using X1d. i discovered that somehow the audio exported from X3c is very much different from what was done during mix-down. There were certain tracks where the levels just dont match at all. Some tracks retained their levels while other didint. When i did a re-export, i got the same results. Checking the mix-down, everything was smooth and levels were prefect.
 
i did some checking and found that on my export profile, every check box was ticked; which was what i have been using since X1d. Because of the recent 64bit Audio issues reported, i decided to uncheck the "Use 64bit Engine"... loh and behold, the 2-track was exactly as it was playing back in X3c during mix-down.
 
Not sure if it's just me or are there any other users who had similar issues???

my workflow is as follows:
1. Midi sequencing - all envelopes and changes done
2. Freeze all synths
3. Mix-down audio - some tracks with audio envelopes
4. All ProChannel enabled - eq, compressors and some with third party plugins
5. Export to 2 Track from "File Menu"
(all the while in Preferences 64bit Audio Engine Disabled - never had it enabled since X1)
 
discovery of 64bit Audio Engine enabled was only made during today's export session
 
do kindly advice...
 
many thanks all!!!