I had asked for a gold guarantee for a return leg which was booked on flex ( the ongoing was saver)..
Initially, they said that its only possible if the full itinerary is on flex, but I said thts not mentioned in the T&C's.. then other excuses..
Then suddenly I got an email asking me to do olci for the other flight I had asked for without any information. I went to my bookings and saw that both the flights were being shown in my bookings and it was not allowing me to do olci..
So I called EK and they said they have confirmed my seat on my requested flights and I needed to pay the change fee .. I did that and was able to do olci then..
Things to note here for future benefit of others :
1. One leg was in Saver and other in Flex.
2. The return leg ( on flex) consisted of one flt ( XXX-dxb) which was fully booked and the next ( dxb-xxx) which had space available. ( This experience is different than what B747 experienced and goes to show how many open questions are there in this benefit)..

Morale of the atory -- persistence pays on some occasions !!