Disappearing mouse click events in linux x64 client

With the 0.5.0-linux_x86_64 teeworlds client some input events seem to dissappear before they are handeled by the client. Sometimes the mouse click does not register (mouse down event is ignored) sometimes the mouse button gets stuck (mouse up event is ignored). It also feels like the mouse movement is somewhat jerky (perhaps mouse move events get lost also).

My OS is 64-bit Ubuntu 8.10, teeworlds version is linux_x86_64.