I know some folks were having problems with saving flight plans created on the FMC. The flight plan would save, but when you call the plan again the plan would show without the legs. I was also having these problems.

I did find a solution.

After creating your flight plan with all legs. Before you save it, go to your departure page and add a rwy for dep. You don't need to have a Departure Procedure, just a rwy number. Then save the flt pln.
When you call up the flight plan, you should have all the legs and you can always change the Departure rwy to the rwy. needed.

Hope I explained this correct and hope it helps.