[libvirt] anyone ever seen virDomainCreateWithFlags() essentially hang?

I'm investigating something weird with libvirt 1.2.17 and qemu 2.3.0. I'm using the python bindings, and I seem to have a case where libvirtmod.virDomainCreateWithFlags() hung rather than returned. Then, about 15min later a subsequent call to libvirtmod.virDomainDestroy() from a different eventlet within the same process seems to have "unblocked" the original creation call, which raised an exception and an error code of libvirt.VIR_ERR_INTERNAL_ERROR. The virDomainDestroy() call came back with an error of "Requested operation is not valid: domain is not running". The corresponding qemu logs show the guest starting up and then a bit over 15min later there is a "shutting down" log. At shutdown time the libvirtd log shows "qemuMonitorIORead:609 : Unable to read from monitor: Connection reset by peer". The parent function did two additional retries, and both the retries failed in similar fashion. In all three caess there seems to be a pattern of the qemu instance starting up but virDomainCreateWithFlags() not returning, then a subsequent virDomainDestroy() call for the same domain causing the virDomainCreateWithFlags() call to get "unblocked" and return -1 leading to an exception in the python code. Any ideas what might cause this behaviour? I haven't reproduced the "hanging" behaviour myself, I'm working entirely off of logs from the affected system. Thanks, Chris