Just tested again and was again able to reproduce on mako:

phablet@ubuntu-phablet:/usr/share/ofono/scripts$ ./list-modems 
[ /ril_0 ]
    Revision = M9615A-CEFWMAZM-2.0.1700.98
    Serial = 353918052313257
    Online = 1
    Type = hardware
    Features = ussd net gprs sms rat sim 
    Emergency = 0
    Model = Fake Modem Model
    Lockdown = 0
    Powered = 1
    Interfaces = org.ofono.CallBarring org.ofono.CallSettings org.ofono.SupplementaryServices org.ofono.NetworkRegistration org.ofono.ConnectionManager org.ofono.Phonebook org.ofono.CallForwarding org.ofono.SmartMessaging org.ofono.PushNotification org.ofono.MessageManager org.ofono.NetworkTime org.ofono.MessageWaiting org.ofono.RadioSettings org.ofono.SimManager org.ofono.CallVolume org.ofono.VoiceCallManager 
    Manufacturer = Fake Manufacturer
    [ org.ofono.CallBarring ]
        VoiceIncoming = disabled
        VoiceOutgoing = disabled
    [ org.ofono.CallSettings ]
        CallingLineRestriction = off
        CalledLinePresentation = disabled
        CallingLinePresentation = enabled
        HideCallerId = default
        ConnectedLineRestriction = unknown
        ConnectedLinePresentation = unknown
        VoiceCallWaiting = enabled
        CallingNamePresentation = unknown
    [ org.ofono.SupplementaryServices ]
        State = idle
    [ org.ofono.NetworkRegistration ]
        CellId = 3198203
        Technology = umts
        MobileCountryCode = 724
        LocationAreaCode = 40248
        Status = registered
        MobileNetworkCode = 06
        Mode = auto
        Name = VIVO
        Strength = 45
    [ org.ofono.ConnectionManager ]
        Attached = 1
        Powered = 1
        RoamingAllowed = 0
        Bearer = hspa
        Suspended = 0
    [ org.ofono.Phonebook ]
    [ org.ofono.CallForwarding ]
        ForwardingFlagOnSim = 0
        VoiceNoReplyTimeout = 30
        VoiceNoReply = +550174891818716
        VoiceUnconditional = 
        VoiceBusy = +550174891818716
        VoiceNotReachable = +550174891818716
    [ org.ofono.SmartMessaging ]
    [ org.ofono.PushNotification ]
    [ org.ofono.MessageManager ]
        ServiceCenterAddress = +550112102010
        Alphabet = default
        Bearer = cs-preferred
        UseDeliveryReports = 0
    [ org.ofono.NetworkTime ]
    [ org.ofono.MessageWaiting ]
        VoicemailMailboxNumber = *555
        VoicemailMessageCount = 0
        VoicemailWaiting = 1
    [ org.ofono.RadioSettings ]
        TechnologyPreference = umts
        FastDormancy = 0
        ModemTechnologies = gsm umts 
    [ org.ofono.SimManager ]
        BarredDialing = 0
        CardIdentifier = 89551090318161348308
        FixedDialing = 0
        MobileNetworkCode = 06
        Retries = 
        LockedPins = 
        SubscriberIdentity = 724064900113482
        PinRequired = none
        MobileCountryCode = 724
        ServiceNumbers = [Policia] = '190' [Defesa Civil] = '199' [Bombeiros] = '193' [Vivo no Mundo] = '+551139598262' [Vivo] = '*8486' [Ambulancia] = '192' 
        SubscriberNumbers = +554891818716 
        Present = 1
        PreferredLanguages = pt es en 
    [ org.ofono.CallVolume ]
        SpeakerVolume = 0
        MicrophoneVolume = 0
        Muted = 1
    [ org.ofono.VoiceCallManager ]
        EmergencyNumbers = 08 000 999 110 112 911 118 119 

phablet@ubuntu-phablet:/usr/share/ofono/scripts$ ./list-contexts 
[ /ril_0 ]
    [ /ril_0/context1 ]
        Active = 0
        Password = vivo
        Preferred = 0
        MessageCenter = http://termnat.vivomms.com.br:8088/mms
        MessageProxy = 200.142.130.104:80
        IPv6.Settings = { }
        AccessPointName = mms.vivo.com.br
        Protocol = dual
        Name = Vivo MMS
        Username = vivo
        Settings = { }
        Type = mms

    [ /ril_0/context2 ]
        AccessPointName = zap.vivo.com.br
        Protocol = dual
        Active = 0
        Name = Vivo Internet
        Username = vivo
        Preferred = 0
        Type = internet
        Settings = { }
        Password = vivo
        IPv6.Settings = { }

phablet@ubuntu-phablet:/usr/share/ofono/scripts$ ifconfig
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1039 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1039 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:109170 (109.1 KB)  TX bytes:109170 (109.1 KB)

phablet@ubuntu-phablet:/usr/share/ofono/scripts$ system-image-cli -i
current build number: 180
device name: mako
channel: ubuntu-touch/devel-proposed
alias: ubuntu-touch/vivid-proposed
last update: 2015-04-21 19:27:48
version version: 180
version ubuntu: 20150421.1
version device: 20150210
version custom: 20150421.1

phablet@ubuntu-phablet:/usr/share/ofono/scripts$ dpkg -l | grep network-manager
ii  network-manager                                      0.9.10.0-4ubuntu15                          armhf        network management framework (daemon and userspace tools)

Waited almost 30 minutes and still nothing.