[Vwdiesel] Sequence to tighten a/c compressor and alternator belts

[ken1]

I have tried three (3) times to tighten the belts on my 1.6l NA. Each time, the a/c belt still flaps a lot. I do not have OEM belts installed at this time, but do have them on hand. First I will state how I have tried to do it, then what I think happens and then need to know what to do to solve the problem.

What I do; remove alternator, put on belts, tighten a/c compressor belt. 
Then replace alternator and tighten the belt. Appears  that by following my steps, when I tighten the alternator belt, the geometry changes and the a/c compressor is moved and the belt gets loose. I can tell that the PO had used a pry-bar to apply tension to the alternator belt, because he wound up bending the top of the front apron in front of the alternator. After performing the same process three (3) times and getting the same results, decided to ask for assistance.
What am I doing wrong???/
Help! Summer has arrived in north Texas, got to have access to cooler air. 

OEM belts are Conti AVX10x643 and Conti AVX13x960.
TIA, 
ken