Before you have a heart attack, I should warn you that I am not the AC posting here. And yes, when linux hibernates, it pushes memory to swap. If you don't have enough swap during a hibernate, the system treats its as a OOM condition, and finds the largest app to close, which is usually X or your browser. Also, if you think that suspend or hibernate "just work" without having to configure your system to do it, then you're a hand-holding fedora/ubuntu user and have no idea how linux really works.