Plugin Version: 0.9.2.9
Minify with the following settings breaks the TwentyEleven Theme, removing indents and causing too small div sizes. Both Wordpress and TwentyEleven are new and unmodified, there are no other plugins except EWWW Image Optimizer and WordPress MU Domain Mapping.
Minify / Mode:Auto
Minify / Cache: APC
Minify / CSS Minifier: Default
HTML & XML / Inline CSS minification: False
CSS / Enable: True
CSS / ...: Bug independent from other settings
I don't plan on using the twenty eleven theme, it was just conspicuous that something broke after installing and configuring the plugin on a fresh wordpress instance.