Yeah as a mater of fact I do. It is a weird glitch but only PROXY servers can work when it comes to LAN servers. The reason why you could connect before may be because it was another update. Also, you might need to reinstall minecraft on BOTH computers. This sometimes works for people. You might also be on different versions of Minecraft when trying to connect. I would look at videos on youtube to try and find the answer. Other than that, you might just not have all computer drivers up to date on one computer.