Hi Sven,
>It wouldn't be a no-op if you stored the modified NumberFormat in the cache: this would change the grouping for all numberformats cloned in succession by the converter, wouldn't it? This is the same as changing the grouping globally.
yes, you are right. Apparently my locale was set to German automatically somehow, even though the preference in Accept-Language is set to EN. This caused my testcase to "work" because it resulted in two different instances of the converter.
Christoph
