openOrderRequestTXT valid on entry order?

Hi,

I created an entry limit order and supplied a value for the custom ID using
valuemap.setString(O2GRequestParamsEnum.CUSTOM_ID, "some value");

When the entry later triggers and my response listener onTradeReceived( O2GResponse response ) method is called, I retrieve the value using
String openOrderRequestTXT = openedTrade.getOpenOrderRequestTXT();

Problem is, for an entry order, this isn't returning anything, but if I open the trade directly (using the API), then I get the value I provided.

So my question is whether this is correct behavior (i.e., CUSTOM_ID is not a valid parameter for an entry order) or if others are not losing the custom ID, so the problem is in my code?

thanks,
Rik