connect checker PROBLEM

Hi :)

I use CATIA since about 20years, and, check Conection between surface is very very important, we use CATIA for precision, but; I have problem since many years, CONECT CHECKER TOOLS is just crazy; give you crazy value dependly you make JOIN or not.

Exemple on 10 surfaces, I check, 0.2mm G0 gap, I make JOIN, all is oki, soo, what is the problem???
If I have make Healing, or JOIN and copy/past in Surface Isolated, no problem, problem come when many surface is nalyse.

Soo, this problem is a BIG PROBLEM, do you know solution? What value is good??? what is true? Waht is rong? 

I use CATIA for precision and soft tell me 0 o big gap everywhere sometime....

PS: Here you can try with this part:
http://catiadoc.free.fr/online/ha1ug_C2/ha1ugbt0200.htm

Thx