Issue using accents


I’m not sure if this is a real bug at all. I write in brazilian portuguese and, therefore, use accents like “´”, “`”, “~” and “^” on vowels. They appear perfectly but when I type, differently from other writing programs, there seems to be some kind of delay on the input of the character (I type fast) which prevents the letter to incorporate the accent. For instance, usually when I type “~” and then “a” to have a “ã”, the result is “a”. Then, I have to retype it slower to get the proper character “ã”.
I couldn’t find any preferences menu in order to change the keyboard speed or something. In other programs like Word or Open Office, it doesn’t happen, which makes me believe that the problem belongs to Scrivener.
I hope you can help me.