Comma in jsoncpp output string

Question

I'm currently using jsoncpp 0.6 for my project. When I tried to serialize a real number (float) into a json file, I noticed that the output string contains a comma instead of a dot as a decimal mark. This causes serious problems when putting real numbers into a json array, because there the comma is used as a separator for the array entries.

You can reproduce it with:

Json::Value testVal(Json::realValue);
testVal = 1.2f;
std::string testString = testVal.toStyledString();

I get 1,200000047683716 instead of 1.200000047683716. Can anyone reproduce this? Any hints would be appreciated.