Wierdo99

I was messing around with 1.7.2 builds and was having problems with the custom GUI associated with containers as well. The only way to get them to open was to force the activation event to trigger on both the client and server. (This is against the code that you see in BlockFurnace, for example). After reading the GIT logs for FML and Forge, there was actually an issue in that the server was not sending the openGui packet to the client. They have fixed this, and the containers now function as expected. The only problem is, they have not released a new build with this fix. So, you would either need to wait for a new build, or compile the source yourself using the code from GIT.