I've been having the same issue for a while as well, however with different hardware.
I use teamviewer to run an Ubuntu machine headless and I connect to it with my Laptop/Desktop/android tablet. I've experienced the 3 hr timeout on both Laptop and Desktop (both Windows 7 64), for the tablet, I've never had teamviewer open long enough to run into it, but wouldn't surprise me if it happens there too.
There is a setting under advanced options that seems like it should affect this (called "Timing out inactive session" which ranges from Off to 8 hours) but changing the setting appears to have no effect. I've tried changing it on both ends of the connection with no luck.
It never happened in Teamviewer 9(?). I can't be sure if it's been this way for all of Teamviewer 10, or started somewhere midway through.
I never found a solution, and sort of just resigned myself to deal with it. I definitely don't connect 24h/day, maybe 2-3 times a week at most. The most frustrating thing about it is when the session ends it pops up windows that take focus away from videos/media playing (this has always been frustrating, but at least previously it was me directly causing the popup, now it just shows up after I forget I had Teamviewer open). Was also surprised at the lack of anyone talking about this issue. I figured even searching just "teamviewer 3 hours" would have got some hits (though believe me I tried many other searches), since it being exactly 3 hours is sort of oddly specific.
My fear is that they added it in as an inconvenience to encourage buyers, but since they don't provide a non-business purchase option that ain't happening. I'd gladly pay $30 or something just to have all the popups (and now this timeout) gone.
Would love to hear if you get a response from your ticket.
