oh shit....
LOL
I have seen that I didn't update to 5pre32 and I was on 5pre30. I don't know why I was convinced I did install the 32 update, but not in the developing portable install...
anyway... the good news is that it seems
it works well in 5pre32 !!!!!
I am mad... mad bug hunter... lol
Mad with myself because I didn't see the changelog in 5.31
v5.0pre31 - May 12 2015
+ Windows: fixed color picker potentially "shown" offscreen
# FX: fixed potential hang on undo [p=1520409]
# Routing window: improved dB value precision [p=1513927]
But at least I am happy now.. another bug hunted
Thank you for your support as always X-Raym