Same issue here. Ubuntu 14.04, Minecraft 1.8.1 w/ Optifine 1.8.1, java version "1.7.0_65" OpenJDK Runtime Environment (IcedTea 2.5.3) (7u71-2.5.3-0ubuntu0.14.04.1) OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode) Alt-tab or any other of these buttons takes me out of minecraft, after which I cannot reenter. The problem does not occur if I am out of fullscreen when these keys are pressed.
Ari Fogel
Same issue here. Ubuntu 14.04, Minecraft 1.8.1 w/ Optifine 1.8.1,
java version "1.7.0_65"
OpenJDK Runtime Environment (IcedTea 2.5.3) (7u71-2.5.3-0ubuntu0.14.04.1)
OpenJDK 64-Bit Server VM (build 24.65-b04, mixed mode)
Alt-tab or any other of these buttons takes me out of minecraft, after which I cannot reenter. The problem does not occur if I am out of fullscreen when these keys are pressed.