From:  guillaume (MRGAG)
344.7 In reply to 344.6 
thank you, I didn't know that ....

maybe you could help on this to : I have just spent half an hour removing double surfaces on my object to be able to propely join surfaces, which I did well, but 5 mn later I saw that my surfaces were not joined anymore !!! it's the third time it happens on the same object

does somedy have a clue about this ?