I have a WordPress 2.7 blog that I had been using with TextMate. Around the time I upgraded WordPress to 2.7.1 and TextMate to 1.5.8 (1498), TextMate lost the ability to interact with my blog. it gives "Error: bad login/pass combination(403)."
I've isolated the issue to when my password contains an ampersand (all the other characters are letters and numbers). For example, when I set the password to abcabc it works, but abc&abc does not.