I broke the main quest in this playthrough. Here's what I did... I decided to do what Yes Man told me and go to Fortification Hill... but since this was my third playthrough and I started it primarily to see if I could rescue Benny from Mr. House, I blew Caesar to smithereens with C4, and fought my way out of the camp. Instead of rooting around a radioactive bunker, I figured it was smarter to just take the platinum chip straight back to House.

Oops. Now both House and Yes Man want me to upgrade the robots, but I can't, since I don't have a platinum chip anymore. It's not necessarily COMPLETELY broken since I can just trash everything in the bunker... but it does svck that you can no longer reactivate the robots, even when Mr. House is telling you to do so!