I'm now able to reproduce this locally, and in each case (either restart or resize), the guest VM itself appears to not be booted. I've added code to dump the console of the guest during the failure, and in each case the recall from Nova comes back with no data in the response body (see below). This leads me to believe this is a problem with the guest after the restart/resize:

2014-06-09 16:14:32.640 30408 TRACE tempest.scenario.test_network_advanced_server_ops AssertionError: Timed out waiting for 172.24.4.16 to become reachable
2014-06-09 16:14:32.640 30408 TRACE tempest.scenario.test_network_advanced_server_ops 
2014-06-09 16:14:32.642 30408 DEBUG tempest.scenario.manager [-] Console output for 86e7e749-83ec-4e39-9a39-3042213569b5 _log_console_output tempest/scenario/manager.py:397
2014-06-09 16:14:32.642 30408 DEBUG novaclient.client [-] 
REQ: curl -i 'http://173.39.225.77:8774/v2/54a724dc112c482e84975fc6c1e3014e/servers/86e7e749-83ec-4e39-9a39-3042213569b5/action' -X POST -H "X-Auth-Project-Id: TestNetworkAdvancedServerOps-1411494319" -H "User-Agent: python-novaclient" -H "Content-Type: application/json" -H "Accept: application/json" -H "X-Auth-Token: MIIRxAYJKoZIhvcNAQcCoIIRtTCCEbECAQExCTAHBgUrDgMCGjCCEBoGCSqGSIb3DQEHAaCCEAsEghAHeyJhY2Nlc3MiOiB7InRva2VuIjogeyJpc3N1ZWRfYXQiOiAiMjAxNC0wNi0wOVQxNjowNDoyNS41MTM2ODkiLCAiZXhwaXJlcyI6ICIyMDE0LTA2LTA5VDE3OjA0OjI1WiIsICJpZCI6ICJwbGFjZWhvbGRlciIsICJ0ZW5hbnQiOiB7ImRlc2NyaXB0aW9uIjogIlRlc3ROZXR3b3JrQWR2YW5jZWRTZXJ2ZXJPcHMtMTQxMTQ5NDMxOS1kZXNjIiwgImVuYWJsZWQiOiB0cnVlLCAiaWQiOiAiNTRhNzI0ZGMxMTJjNDgyZTg0OTc1ZmM2YzFlMzAxNGUiLCAibmFtZSI6ICJUZXN0TmV0d29ya0FkdmFuY2VkU2VydmVyT3BzLTE0MTE0OTQzMTkifX0sICJzZXJ2aWNlQ2F0YWxvZyI6IFt7ImVuZHBvaW50cyI6IFt7ImFkbWluVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzQvdjIvNTRhNzI0ZGMxMTJjNDgyZTg0OTc1ZmM2YzFlMzAxNGUiLCAicmVnaW9uIjogIlJlZ2lvbk9uZSIsICJpbnRlcm5hbFVSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo4Nzc0L3YyLzU0YTcyNGRjMTEyYzQ4MmU4NDk3NWZjNmMxZTMwMTRlIiwgImlkIjogIjEyYWVlMDc2M2E2ZTRkMDFiMTc0ZTMyMWQ0NTIxZjRiIiwgInB1YmxpY1VSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo4Nzc0L3YyLzU0YTcyNGRjMTEyYzQ4MmU4NDk3NWZjNmMxZTMwMTRlIn1dLCAiZW5kcG9pbnRzX2xpbmtzIjogW10sICJ0eXBlIjogImNvbXB1dGUiLCAibmFtZSI6ICJub3ZhIn0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6OTY5Ni8iLCAicmVnaW9uIjogIlJlZ2lvbk9uZSIsICJpbnRlcm5hbFVSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo5Njk2LyIsICJpZCI6ICIzOTJjY2Y3MzAwYzc0ZThhYjI5ZTA2YTUyZTFlOWEwYyIsICJwdWJsaWNVUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6OTY5Ni8ifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAibmV0d29yayIsICJuYW1lIjogIm5ldXRyb24ifSwgeyJlbmRwb2ludHMiOiBbeyJhZG1pblVSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo4Nzc2L3YyLzU0YTcyNGRjMTEyYzQ4MmU4NDk3NWZjNmMxZTMwMTRlIiwgInJlZ2lvbiI6ICJSZWdpb25PbmUiLCAiaW50ZXJuYWxVUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODc3Ni92Mi81NGE3MjRkYzExMmM0ODJlODQ5NzVmYzZjMWUzMDE0ZSIsICJpZCI6ICIwY2ZkMTkyMjNmYzc0YTkzYjAyZDI5MTg3ODkxMzc1ZSIsICJwdWJsaWNVUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODc3Ni92Mi81NGE3MjRkYzExMmM0ODJlODQ5NzVmYzZjMWUzMDE0ZSJ9XSwgImVuZHBvaW50c19saW5rcyI6IFtdLCAidHlwZSI6ICJ2b2x1bWV2MiIsICJuYW1lIjogImNpbmRlcnYyIn0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODc3NC92MyIsICJyZWdpb24iOiAiUmVnaW9uT25lIiwgImludGVybmFsVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzQvdjMiLCAiaWQiOiAiOWMzNzQ2ZDdlZGViNDc2MWE1Njk5NzJmNmQzZjhkNTAiLCAicHVibGljVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzQvdjMifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAiY29tcHV0ZXYzIiwgIm5hbWUiOiAibm92YXYzIn0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6MzMzMyIsICJyZWdpb24iOiAiUmVnaW9uT25lIiwgImludGVybmFsVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjMzMzMiLCAiaWQiOiAiMWUyYjcyMDAzYTIzNDYwM2IzYTRhM2M0Mjc5OTk5YjYiLCAicHVibGljVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjMzMzMifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAiczMiLCAibmFtZSI6ICJzMyJ9LCB7ImVuZHBvaW50cyI6IFt7ImFkbWluVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjkyOTIiLCAicmVnaW9uIjogIlJlZ2lvbk9uZSIsICJpbnRlcm5hbFVSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo5MjkyIiwgImlkIjogIjFmZDc4MWQ0MTkxMzQwOTM5MTYxYzdiNTI3ODVhZDZkIiwgInB1YmxpY1VSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo5MjkyIn1dLCAiZW5kcG9pbnRzX2xpbmtzIjogW10sICJ0eXBlIjogImltYWdlIiwgIm5hbWUiOiAiZ2xhbmNlIn0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODAwMC92MSIsICJyZWdpb24iOiAiUmVnaW9uT25lIiwgImludGVybmFsVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjgwMDAvdjEiLCAiaWQiOiAiNjBkNDFiNDFkY2QxNDk3OWIyZDJjMjBjNmZhMjlmYjgiLCAicHVibGljVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjgwMDAvdjEifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAiY2xvdWRmb3JtYXRpb24iLCAibmFtZSI6ICJoZWF0In0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODc3Ni92MS81NGE3MjRkYzExMmM0ODJlODQ5NzVmYzZjMWUzMDE0ZSIsICJyZWdpb24iOiAiUmVnaW9uT25lIiwgImludGVybmFsVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzYvdjEvNTRhNzI0ZGMxMTJjNDgyZTg0OTc1ZmM2YzFlMzAxNGUiLCAiaWQiOiAiNDA4ZWI5ZWE2MzA1NGEwNWJlZGIzYzFlNzE3NjBjZjAiLCAicHVibGljVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzYvdjEvNTRhNzI0ZGMxMTJjNDgyZTg0OTc1ZmM2YzFlMzAxNGUifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAidm9sdW1lIiwgIm5hbWUiOiAiY2luZGVyIn0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODc3My9zZXJ2aWNlcy9BZG1pbiIsICJyZWdpb24iOiAiUmVnaW9uT25lIiwgImludGVybmFsVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzMvc2VydmljZXMvQ2xvdWQiLCAiaWQiOiAiMjVlNjU4YTMyNDBhNDIzMjhlNGMzMjYxMTk3YTFkYmUiLCAicHVibGljVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3Ojg3NzMvc2VydmljZXMvQ2xvdWQifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAiZWMyIiwgIm5hbWUiOiAiZWMyIn0sIHsiZW5kcG9pbnRzIjogW3siYWRtaW5VUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6ODAwNC92MS81NGE3MjRkYzExMmM0ODJlODQ5NzVmYzZjMWUzMDE0ZSIsICJyZWdpb24iOiAiUmVnaW9uT25lIiwgImludGVybmFsVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjgwMDQvdjEvNTRhNzI0ZGMxMTJjNDgyZTg0OTc1ZmM2YzFlMzAxNGUiLCAiaWQiOiAiMzQzN2U5MWRmMTc5NDJlNzk0NTU1YjAyYTA5NGFhYjYiLCAicHVibGljVVJMIjogImh0dHA6Ly8xNzMuMzkuMjI1Ljc3OjgwMDQvdjEvNTRhNzI0ZGMxMTJjNDgyZTg0OTc1ZmM2YzFlMzAxNGUifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAib3JjaGVzdHJhdGlvbiIsICJuYW1lIjogImhlYXQifSwgeyJlbmRwb2ludHMiOiBbeyJhZG1pblVSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43NzozNTM1Ny92Mi4wIiwgInJlZ2lvbiI6ICJSZWdpb25PbmUiLCAiaW50ZXJuYWxVUkwiOiAiaHR0cDovLzE3My4zOS4yMjUuNzc6NTAwMC92Mi4wIiwgImlkIjogIjFmOTdiNDA1NjRjOTQzZDU5MjcyMTA0YjgwZTg1NDQ4IiwgInB1YmxpY1VSTCI6ICJodHRwOi8vMTczLjM5LjIyNS43Nzo1MDAwL3YyLjAifV0sICJlbmRwb2ludHNfbGlua3MiOiBbXSwgInR5cGUiOiAiaWRlbnRpdHkiLCAibmFtZSI6ICJrZXlzdG9uZSJ9XSwgInVzZXIiOiB7InVzZXJuYW1lIjogIlRlc3ROZXR3b3JrQWR2YW5jZWRTZXJ2ZXJPcHMtMzQ5NTc3NjgyIiwgInJvbGVzX2xpbmtzIjogW10sICJpZCI6ICI1Mzg3YjdjM2YzMDA0ZjY1YTg2YTg0YmNmMDdjOTNhZCIsICJyb2xlcyI6IFt7Im5hbWUiOiAiX21lbWJlcl8ifV0sICJuYW1lIjogIlRlc3ROZXR3b3JrQWR2YW5jZWRTZXJ2ZXJPcHMtMzQ5NTc3NjgyIn0sICJtZXRhZGF0YSI6IHsiaXNfYWRtaW4iOiAwLCAicm9sZXMiOiBbIjlmZTJmZjllZTQzODRiMTg5NGE5MDg3OGQzZTkyYmFiIl19fX0xggGBMIIBfQIBATBcMFcxCzAJBgNVBAYTAlVTMQ4wDAYDVQQIDAVVbnNldDEOMAwGA1UEBwwFVW5zZXQxDjAMBgNVBAoMBVVuc2V0MRgwFgYDVQQDDA93d3cuZXhhbXBsZS5jb20CAQEwBwYFKw4DAhowDQYJKoZIhvcNAQEBBQAEggEAAnVjb6K7gbLqwgl5IROR5CHkaIu+NvcGkTXt7sUjU98CCcYP4uEClYb5ivxRQpzJv44+IOArB439Cr9hPOEJD+dAXD6V3DuNXVYvAypcL72TMkOV77LDMTKIYUNvJPY0K9F8dWGxA-jaLI6y-Dek2VSzwiKUcL7xDhzj9srnXL7lks12DZ0LW8SKQb2F1jxL6vcJzOaz5NGSt5NyPtK4gtjg+-W30gZEriBHzwYX+lKS3V4J5UrwoatkA4I-BJ+SUfMNGlKxKeUm7akccMSrQ7iD2aXQcNzYQ8SIG3bTS0zhtkRKcDFdyRUgTMV4Kpk5XgG5yodANeMbwXoK7aQgsg==" -d '{"os-getConsoleOutput": {"length": null}}'
 http_log_req /opt/stack/python-novaclient/novaclient/client.py:181
2014-06-09 16:14:32.758 30408 DEBUG novaclient.client [-] RESP: [200] CaseInsensitiveDict({'date': 'Mon, 09 Jun 2014 16:14:32 GMT', 'content-length': '14', 'content-type': 'application/json', 'x-compute-request-id': 'req-f24c4321-5cfa-46f5-93a6-636fe19f7daf'})
RESP BODY: {"output": ""}