I thought this was the case as well, that you could replay the missing modes, then start SOS again. I'm not a good enough player to get into this situation very often, though.

While testing Eli's fiber mod, however, I ran into the same thing you mention. After relighting the modes, I couldn't restart SOS. Maybe it changed from v1.7 to v1.74.

I've only owned Tron for a few weeks, but all I know is I was able to get to SOS twice in one game, but I'm not sure what I did to get there.

To play SOS again you need to start each of the objectives again. So in addition to "CLU", "Zuse", and "Light Cycle", you will need to start Quorra,GEM,Flynn,Discs mb, recognizer and TRON. Then the scoop will be lit for SOS again.

We had a lengthy discussion about this several months ago. After some testing we figured out that in addition to replaying all the modes that got extinguished when SOS ends, you must also start each of the 3 multiball modes once. After that SOS will light. You don't have to replay any of the non-multiball modes that you already have lit solidly. There may be more to it that this but you absolutely don't have to replay everything to get SOS to relight.

I've had Tron for a few weeks and just got SoS twice in the same game. This mode is tough as hell. I will keep trying until I reach Portal. Great game!

I got there last night for maybe my 4th time and, like always, could not get past GEM. That stinking GEM shot is my nemesis. I can very rarely light it solid during the game and when I do I never make it to SOS. Most of the time I can't even get her started.

At this point with my skill level, I doubt making it to SOS twice in one game will be anything I need to concern myself with any time soon. Heck, twice in one night might be nice!