Thanks theblackjack. I'm not completely sure how is the current status of this issue. In new instalations of Xubuntu 12.04 is seems that the default behaviour is, finally, print ç for 'c for the US-international-with dead keys layout. I have the impresion however that the problem persists in some applications, as libreoffice. But I would need to test this on a clean instalation, and currently I cannot do so. Anyway, it seems that someone has heard our claims.
Thanks theblackjack. I'm not completely sure how is the current status of this issue. In new instalations of Xubuntu 12.04 is seems that the default behaviour is, finally, print ç for 'c for the US-internationa l-with dead keys layout. I have the impresion however that the problem persists in some applications, as libreoffice. But I would need to test this on a clean instalation, and currently I cannot do so. Anyway, it seems that someone has heard our claims.