set font issue on iOS5

[foxling]

i set font with system font, but it look like as bold font:

UIFont *font = [UIFont systemFontOfSize:14];
CTFontRef fontRef = CTFontCreateWithName((__bridge CFStringRef)font.fontName, font.pointSize, NULL);
id ctfont = (__bridge id)(fontRef);
_defaultAttributes = @{(id)kCTForegroundColorAttributeName: (id)[UIColor colorWithHexString:@"#474747"].CGColor, (id)kCTFontAttributeName: ctfont};