Thanks, I've read that article half a dozen times already. It was the most helpful and the most recent. The settings in both the locations referenced in that article are :20 minutes on my server. I'd like to figure out why my testing does not match this value, though.
In the comments, I've also read the reply that you commented on, but can't make sense of what dgaughran was talking about. I think he's referencing IIS, but I'm not sure. I've also checked through a bunch of our tps.config files without any luck.
In the end, I might just have to try the JS update to keep sessions alive. I'll update if that does the trick. Thanks for the reply.