Please help (PT instrument related)

[shabbar3]

Hey guys so something real odd is happening in one of my session. I used 4 structure free instruments on these tracks. And I tracked it, recorded and basically it all worked just fine...now, yesterday I added another one (5th one) and then it said "Structure free does not allow more then 4"..I was like ok, then i deleted the new one (5th one). Now i thought everything was back to normal but basically all those 4 other strucure tracks were not playing the notes that I wrote for it (midi). I restarted pro tools and still same issue. I deleted all the strucutre tracks and started all over and STILL the sounds arent being played? but now sometning else happened, I used another patch of sounds and it works just fine!! but the old sound patch is now like dead or something, when i browse and transfer and play the keys its just "nothign"..please help if anyone knows what to do
Thanks, Shabbar