I believe that your roots may be getting frozen by colder temperatures, and a heat mat may be the solution.

It's also important not to water it too much through the winter since they cannot take in that much water with lower light/temps.

I've ended up selling dozens of a titanums through eBay through 2015 and got rid of all but one of them which I'm keeping by a windowsill myself. I'm finding that the ones that get browning do have their roots stressed whether it is due to overwatering, transplanting, or too shock from too much sun. That is usually followed by a dormancy period, and it's only good to activate it again when you can provide it with warmer temperatures, and brighter light.

Here's the one I still have.

<a href="http://s832.photobucket.com/user/stevelau1911/media/DSC02524_zpsemcmh6ox.jpg.html"; target="_blank"><img src="http://i832.photobucket.com/albums/zz246/stevelau1911/DSC02524_zpsemcmh6ox.jpg"; border="0" alt=" photo DSC02524_zpsemcmh6ox.jpg"/></a>

By the way, do you happen to be Adam Price from Indiana? I did send there 8 months ago so I was just wondering if it is you.

Thank you so much for the advice! I was afraid the cold would be a problem, I was hoping it would go dormant by winter, but it's still going. The only thing that I'm still confused about is the fact that it was doing this during the summer as well. Is it safe to let it dry out a bit, if it's being overwatered?

And no, I'm not, but what a coincidence. I actually got my titan arum from the manager of a greenhouse I used to work at. He had about a dozen seedlings on their second or third petiole. I believe mine's on it's third.

They don't mind being on the dryer side as long as it is not completely dry.