You surely know those non-ASCII characters, don't you? You know, the ones that people post on their facebook wall, the hearts and diamonds and notes... Many people use them also in their passwords, believing that this radically increases the password strength against a brute-force attack. This may be half true though:
|...after creating an account with the password 'ДДДДДДДД', I was able to successfully log in by typing '簡簡簡簡簡簡簡簡,' as well as 'ႤႤႤႤႤႤႤႤ', '©©©©©©©©'. It turns out that any string of exactly 8 characters whose unicode code point is >= 128 will be accepted.|
So what this means is that, there are systems that may not really distinguish the non-ASCII characters. So, no matter how many different characters you enter, they are all read as one same character. As a result, using non-ASCII characters may result in increased password strength due to the addition of an extra non-keyboard digit, but having multiple different non-ASCII characters could make no difference at all.
What can you do? Test your password by replacing you non-ASCII character with another non-ASCII character and see if it works.