Q: So it's user-specific - now what?

Note: I'm coming from the "how to troubleshoot iSight" page here.

I have a MacBook Pro that I've had for a little over a year (I got it in January of 2011 I believe). I've also seen this mentioned, and I do not, nor have I ever, used iChat.

Anyway, I've been having this issue for a few weeks where my iSight will not function as a camera, but appears to work just fine in other ways. I have my computer set to change the brightness of my screen as the ambient light in the room changes; this still works. However, when I try to use any application (online, like Facebook, or downloaded on my computer, such as Skype or PhotoBooth) it says there's no camera connected.

At this point, I have tried everything on the troubleshooting page. Eventually I created a new account on my computer and used photobooth from that new account. It works just fine there, but not on my main account, where all my stuff is. The troubleshooting page says only that this is "isolated to user settings." My question is: where in user settings? I've been searching for an hour and I can't find any place on my computer where I can change the settings relating to a camera. For example, in system preferences, there is an option for Audio settings, but no such thing for video.

I would also like to mention that I have seen EZ Jim's response to the same problem here, and, not to call you out EZ Jim, but I just don't like that response. If my account is "damaged" then shouldn't I try to figure out what damaged it and actually solve the problem, rather than a) make a lot of work for myself moving my files/programs and b) creating the potential to have the same problem again in the future on my new account? If it happens again, I don't want to constantly be hopping from one account to the next. I just want to fix it.

My issue is that the troubleshooting page clearly says it's a user Settings issue, so where are the settings that would enable or disable the iSight? This seems to be a common problem - is there a specific program that people download that seems to corrupt your user account? (Of note: the only downloaded programs I've really ever used the camera in before are Photobooth and Skype.)

I'm aware this might be kind of a big issue and I'm probably going to call the support hotline, or just go to an actual Apple store and ask about this, if I have to. Both are viable options right now. I just think it would be great to save myself a two-hour drive (to the Apple store) or a bunch of potentially wasted mintues on my phone if I can fix it myself.

Thanks in advance.