I think we'll need to pull in someone from Steam since Valgrind reports some mismatched frees in vgui2_s.so, steamclient.so and steamui.so. There are not debug symbols so impossible to guess what area of the code is that. Then this also looks pretty bad: ERROR: ld.so: object '/home/vedran/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored. ERROR: ld.so: object '/home/vedran/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored Please if someone knows any Steam devs CC them here?