Hi all. I hope this is the right place for me to raise my issue. After doing a pacman -Syu and then rebooting I noticed that I could no longer start my VirtualBox vms I get the following error: Failed to open a session for the virtual machine My_VM Callee RC: NS_ERROR_INVALID_ARG (0x80070057) Virtualbox then crashes (segmentation fault). I had the testing repo enabled, so I thought that one of the packages from testing might have broken it. So I disabled the testing repo in pacman.conf and removed all testing packages with: pacman -Syy pacamn -Suu I then recompiled my virtualbox drivers and rebooted. But that did not help at all. I created a core dump file by following these instructions: http://www.virtualbox.org/wiki/Core_dump So the stack trace is 41000 lines long :-| I'll paste just the first and last few lines: #0 0xb5cad825 in ?? () from /usr/lib/libQtGui.so.4 #1 0xb5ca7b27 in ?? () from /usr/lib/libQtGui.so.4 #2 0xb5ca9760 in QTextEngine::itemize() const () from /usr/lib/libQtGui.so.4 #3 0xb5caeca8 in QTextLayout::beginLayout() () from /usr/lib/libQtGui.so.4 #4 0xb5b9b550 in ?? () from /usr/lib/libQtGui.so.4 #5 0xb5b9c1b1 in ?? () from /usr/lib/libQtGui.so.4 [snip] #41537 0xb5a36407 in QApplication::exec() () from /usr/lib/libQtGui.so.4 #41538 0xb6b5405b in TrustedMain () from /usr/lib/virtualbox/VirtualBox.so #41539 0x08048d9f in ?? () #41540 0xb76ccc76 in __libc_start_main () from /lib/libc.so.6 #41541 0x08048c81 in ?? () Any advice? Should I file a bug in the arch bug tracker? Thanks in advance. Pico