Getting the following error when attempting to start a new instance from an ISO in CloudStack using devcloud. This occurs in master and 4.1 branch.

gistfile1.txt

2013-05-28 18:31:49,730 DEBUG [xen.resource.CitrixResourceBase] (DirectAgent-242:null) 1. The VM i-2-10-VM is in Starting state.
2013-05-28 18:31:49,734 DEBUG [xen.resource.CitrixHelper] (DirectAgent-242:null) Can't find the guest os: Ubuntu 12.04 (64-bit) mapping into XCP's guestOS type, start it as HVM guest
2013-05-28 18:31:49,786 DEBUG [xen.resource.CitrixResourceBase] (DirectAgent-242:null) Created VM 45f12dd2-39c3-647a-8ac0-3eeab5fa63cb for i-2-10-VM
2013-05-28 18:31:49,892 DEBUG [xen.resource.CitrixResourceBase] (DirectAgent-242:null) VBD fe4a1b35-f077-78bf-0514-8ca3fd448b0d created for Vol[11|ROOT|a631590f-58cf-4078-9582-5648b84cbed9|5368709120]
2013-05-28 18:31:51,077 DEBUG [xen.resource.CitrixResourceBase] (DirectAgent-242:null) VBD a5c6b142-26dc-2d7f-358e-0f0b443a2c9d created for Vol[10|ISO|nfs://192.168.56.10:/opt/storage/secondary/template/tmpl//2/202//202-2-88eeeaea-42eb-336f-8d37-19200f33f327.iso|0]
2013-05-28 18:31:51,077 DEBUG [xen.resource.CitrixResourceBase] (DirectAgent-242:null) Creating VIF for i-2-10-VM on nic [Nic:Guest-192.168.56.134-vlan://untagged]
2013-05-28 18:31:51,112 DEBUG [xen.resource.CitrixResourceBase] (DirectAgent-242:null) Created a vif 6a0b1676-b043-facf-bfd8-3a6ce2aa8012 on 0
2013-05-28 18:31:51,925 DEBUG [cloud.api.ApiServlet] (383841963@qtp-325174786-15:null) ===START===  0:0:0:0:0:0:0:1%0 -- GET  command=queryAsyncJobResult&jobId=5aa4db75-0a00-4b48-a5dd-9de1008b89bc&response=json&sessionkey=ihfmnBudO2fwQTscNlHjTT7l2i8%3D&_=1369780311922
2013-05-28 18:31:51,944 DEBUG [cloud.api.ApiServlet] (383841963@qtp-325174786-15:null) ===END===  0:0:0:0:0:0:0:1%0 -- GET  command=queryAsyncJobResult&jobId=5aa4db75-0a00-4b48-a5dd-9de1008b89bc&response=json&sessionkey=ihfmnBudO2fwQTscNlHjTT7l2i8%3D&_=1369780311922
2013-05-28 18:31:52,140 WARN  [xen.resource.CitrixResourceBase] (DirectAgent-242:null) Task failed! Task record:                 uuid: 27e0cb48-9d19-62c8-5754-a4cff87f0057
           nameLabel: Async.VM.start_on
     nameDescription: 
   allowedOperations: []
   currentOperations: {}
             created: Tue May 28 18:31:50 EDT 2013
            finished: Tue May 28 18:31:50 EDT 2013
              status: failure
          residentOn: com.xensource.xenapi.Host@3ba61fa8
            progress: 1.0
                type: <none/>
              result: 
           errorInfo: [VM_HVM_REQUIRED, OpaqueRef:853d92f3-cc5a-f7f4-12f6-cde1f8048795]
         otherConfig: {}
           subtaskOf: com.xensource.xenapi.Task@aaf13f6f
            subtasks: []

2013-05-28 18:31:52,147 WARN  [xen.resource.CitrixResourceBase] (DirectAgent-242:null) Unable to start VM(i-2-10-VM) on host(9d4c9db8-32f7-25c3-0435-eab4bf3adcea) due to Task failed! Task record:                 uuid: 27e0cb48-9d19-62c8-5754-a4cff87f0057
           nameLabel: Async.VM.start_on
     nameDescription: 
   allowedOperations: []
   currentOperations: {}
             created: Tue May 28 18:31:50 EDT 2013
            finished: Tue May 28 18:31:50 EDT 2013
              status: failure
          residentOn: com.xensource.xenapi.Host@3ba61fa8
            progress: 1.0
                type: <none/>
              result: 
           errorInfo: [VM_HVM_REQUIRED, OpaqueRef:853d92f3-cc5a-f7f4-12f6-cde1f8048795]
         otherConfig: {}
           subtaskOf: com.xensource.xenapi.Task@aaf13f6f
            subtasks: []

Task failed! Task record:                 uuid: 27e0cb48-9d19-62c8-5754-a4cff87f0057
           nameLabel: Async.VM.start_on
     nameDescription: 
   allowedOperations: []
   currentOperations: {}
             created: Tue May 28 18:31:50 EDT 2013
            finished: Tue May 28 18:31:50 EDT 2013
              status: failure
          residentOn: com.xensource.xenapi.Host@3ba61fa8
            progress: 1.0
                type: <none/>
              result: 
           errorInfo: [VM_HVM_REQUIRED, OpaqueRef:853d92f3-cc5a-f7f4-12f6-cde1f8048795]
         otherConfig: {}
           subtaskOf: com.xensource.xenapi.Task@aaf13f6f
            subtasks: []

  at com.cloud.hypervisor.xen.resource.CitrixResourceBase.checkForSuccess(CitrixResourceBase.java:3177)
	at com.cloud.hypervisor.xen.resource.CitrixResourceBase.startVM(CitrixResourceBase.java:3289)
	at com.cloud.hypervisor.xen.resource.CitrixResourceBase.execute(CitrixResourceBase.java:1314)
	at com.cloud.hypervisor.xen.resource.XcpOssResource.execute(XcpOssResource.java:143)
	at com.cloud.hypervisor.xen.resource.CitrixResourceBase.executeRequest(CitrixResourceBase.java:517)
	at com.cloud.hypervisor.xen.resource.XcpOssResource.executeRequest(XcpOssResource.java:137)
	at com.cloud.agent.manager.DirectAgentAttache$Task.run(DirectAgentAttache.java:186)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:439)
	at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
	at java.util.concurrent.FutureTask.run(FutureTask.java:138)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:98)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:206)
	at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
	at java.lang.Thread.run(Thread.java:680)

did you find a workaround? I'm hitting the same issue :(