Did you also disable the "right light" settings? They are in a different tab than all the regular settings...

if you don't have anything on auto like you say you don't, its because Lego is a tiny bit reflective and when lights bounces of, it can change everything around it even if you have stuff on manual. That happens to me to. it especially sucks that that happens when I'm doing masking and the base plate changes colors.

Once again, everything is on manual! And anti-flicker is off.
@LTW The strange part is that the place that changes lighting is the background, not lego.
I have a poster board painted with pastels, and the brown colored area in the corner of it is the part that goes brighter/darker.
But thanks anyway.

Good guess. But I'm not that dumb. Well, not quite.   Let's take one of my clips for an example on the lighting problem:

The before mentioned camel is walking onto a set that is approx. 15 inches wide and about twenty deep.
He is walking very slowly, so at 15 fps he's front foot is only on the forth visible dot on-screen. He is also approx. 20 dots away from the camera (six inches or so). The above action is placed at frame #62.
Then from frames 63-69 the brown places on the background (one right in front of the camel, one on the complete other side of the set, and three in between, all about 18-20 inches away from the cam) get slightly brighter, then from 70 onward the brown spots are even brighter. And at frame 70 he is half-way on the 6th dot. (Yes I know, that's a slow walk cycle.)

Now there were three (really four) stages: All before Frame 63:Brown is normal, Frame 63-69: The brown is brighter and stays that way until Frame 70 where it becomes even brighter and remains that way until near the end of the clip (Frame 157) but after frame 157 the brown flickers randomly in between the three different shades until the end of the clip at frame 176. And the camel ends on the 18th dot from the side of the set.

If you can't understand that, then I'll just have to join flickr and put up pics of the problem.

I've got SMA open right now and I'm looking straight at the Logitech Webcam Controller. It says RightLight, RightSound, auto-focus and follow my face are all off. I've also done a little test with those exact settings. With nothing on the set the spots are normal, with the Camel they're brighter, with Jabba the Hut they're normal and with the black ARF trooper they're bright.

I see what you mean by a "film" over the scene, but that's just the exposure (I think) getting brighter.
But please let me clarify, the bright "Spots" are just where I notice the change the most, the rest of the screen lightens as well, but not as much.

I'm wondering if the software is messed up. But I have reinstalled it.

Yes, I've gone into the middle tab there, all through SMA, and everywhere else that I can think of.

I believe those are the same thing. and I have checked there.

And yes, I have the newest version with the white balance.
In fact, I just checked for updates and downloaded the newest one. (That was after this problem came up, and  itdid nothing to fix it.)

They're GE brand, 40 watt, incandescent and "Reveal" (Supposedly not as "yellow-looking" as Soft-white.)

I've also used these bulbs for quite some time, they were even lighting up most of the shots in "Star Wars: The War Without End" and that means they're probably over a year old!