I got a crash with this stack: ----------------- lwp# 1 / thread# 1 -------------------- 00007fffff312a6c xenStoreDomainReleased () + 24 00007fffff312774 xenStoreWatchEvent () + 6c 00000000004181fb virEventDispatchHandles () + 4cb 0000000000418651 virEventRunOnce () + 139 000000000041bc1e qemudOneLoop () + e 000000000041be7b qemudRunLoop () + 13b 000000000041dd43 main () + 6cb 0000000000416f1c ???????? () It looks to me like activeDomainList became NULL. But we've already removed this watch by this point in xenStoreClose(). I'm not au fait with the event locking - does the watch removal need the event lock, or something? thanks john