The omnidroid model that defeated mr incredible was the model 09, a smaller version of the omnidroid, the one that syndrome send to the city was the omnidroid 10, what do you think it happend to the omnidroid 09?Dont you think that maybe it could fall in the wrong hands and be used for destruction again?
Thats a good question… but I think that after Mr. Incredible destroyed it Syndrome realized that he needed an even better robot so he just plain got rid of the old one. Also Syndrome’s base is pretty top secret so I dont think that anyone could steal the omnidrod 9. 
I think he remodeled the Omnidroid 9 and made modifications, and thus, creating OMnidroid 10.
That’s a pretty good theory, but would Syndrome have had time to dismantle such a massive machine before Bob returned to the island?
Maybe he just left it alone for a while and planned to take care of it later…
While we’re talking about what happened to the Omnidroid 9, what happened to all of the other Omnidroids? ( 1-8 )
Well after Bob dismantles the robot theres the Lifes Incredible Again Montage which is suposed to take place over a couple of months and then after the montage is over then Bob goes back to the island and meets the OMnidrod 10 . Over those two months I think Syndrome either remodeled the old one or just created a new one. 
Maybe Syndrome used the omnidriod 10 to destroy the model 09, just for fun
They were destroyed by the heroes that beat them, I hope.
I agree with MB; he just took it apart.
The thing is, I think Omnidroid 9 looks like Omnidrid 10, just a little bigger and more intelligent.
^ …I think you have that backwards…
Yeah, I meant that Omnidorid 10 is bigger, and more intelligent.