Well, I'm not sure I understand exactly what the "texture correction" entails, but I've done a few GI renders and haven't had any problems. Sometimes textures or lighting setups need to be tweaked here and there, but nothing has been noticably wrong.

Also, unless this is part of an animation, or there are other elements / lighting effects that you intend to show in your image, you really don't need to be using GI. I don't see anything in your image that couldn't be achieved by putting a spot beneath the scene set to not cast shadows, a couple spots outside the scene also w/ shadows off, and then adding a few bulb lights as needed around the space.

In fact, the underside of the microscope where the lenses protrude from is so dark, that it almost looks as if you're not using GI at all. So why take the hit in render time if you're not going to reap the benefits visually?

Just a thought. I don't mean to bust on you choice of execution or anything. There may be an element I'm not aware of that led you to this decision. OK, stepping off soap box now. : )

I still love the detail on the lenses.

-pix