I had the same problem and came here to see if others experienced this as well.
I have TubePress v3.1.6 installed on multiple web sites, and when I updated to 3.1.7 all the sudden can only see 3 videos.
I deactivated it and deleted it, then reinstalled v3.1.6, and it works again, no problem.
(except now I have to remember to ignore the update plugin notifications).
Why on earth would you decide all the sudden to limit the videos to just 3, without ANY warning or explaination when upgrading, when you have allowed it to display more videos prior to now???
I fully realize that in order to provide ongoing support and developement you need to make money, as well as offer an incentive for people to upgrade to enable more features... but doing so by REMOVING or DISABLING existing features - rather then by offering more new and improved features in the Pro version... is just plain WRONG. Removing existing features to now require an upgrade is bordering on being just another form of "bait & switch".
This will only result in more people becoming frustrated that it doesn't work, getting upset, and uninstalling the plugin and finding another plugin to handle videos on Wordpress.
I have seen plenty of other new video plugins for wordpress lately, and tactics like this are simply going to drive more of your existing satisfied users to seek other plugins and solutions, rather then motivating them to upgrade to TubePress Pro.
I doubt that I am alone or even in the minority in feeling this way, and expect that you will be seeing many more potential upgrade customers posting here with similar feelings... as well as the many lost potential customers who simply get frustrated, think it is broke, and do not even seek answers on this forum.
I have been a big fan of TubePress... and have been planning on upgrading... but I have simply downgraded to solve the problem for now, and am now considering looking for alternative plugins.