Scientific numbers, like 1e-06, are parsed incorrectly.
From quick glance into ParserCSS30.jjt the DIMENSION rule is commented out. Which, as of spec, seems to reflect the handling of scientific numbers.
Any reason why this is commented out?

In my current project i do not have any control over the incoming CSS (since it is "provided" by the browser and as such it can happen that very small floating values end up in this scientific notation)