When running the driver compiled for Windows with German locale settings, the syntax for float doesn't work:

In the German locale setting, the decimal point is the comma ( , ).

With this set, the driver throws the following error:
Invalid float literal: 2.0 return get_caster_level(source) / 3 * 2.0 / get_speed() / 2

But using the locale-correct version doesn't work, neither, because the comma ( , ) is an integral part of C, as shown in this example:
foo(1,5)

It seems better to keep the english decimal point ( . ) the comma in the source code, ignoring locale settings.