Sounds something like ParseSingle() expecting numbers to use comma instead of period as the decimal point. Try specifically setting C#'s culture info to en-US before doing the BVH calls. ParseSingle() should then recognize the format as being correct.
System.Globalization.CultureInfo timeCultureUS = new System.Globalization.CultureInfo("en-US");
Thread.CurrentThread.CurrentCulture = timeCultureUS;
Thread.CurrentThread.CurrentUICulture = timeCultureUS;
//BVH related things here