错误(不兼容的字符编码:UTF-8和ASCII-8BIT)

I am using Ruby 1.9.2, Rails 3.0.4/3.0.5 and Phusion Passenger 3.0.3/3.0.4. My templates are written in HAML and I am using the MySQL2 gem. I have a controller action that when passed a parameter that has a special character, like an umlaut, gives me the following error:I am using Ruby 1.9.2, Rails 3.0.4/3.0.5 and Ph