Child domain new cert request - certificate template permissions do not allow current user to enroll 0x80094012

I have the following AD configuration:

rootca (standalone not domain connected)

• mydom.local
  • dc1.mydom.local
  • svr1.mydom.local
  • subca.mydom.local(enterprise subordinate CA)
  • other.mydom.local
    • dc1.other.mydom.local
    • svr1.other.mydom.local

I can register webserver certificates OK for svr1.mydom.local, however I log into svr1.other.mydom.local with the child domain administrator and I get the following error:

Permissions on the certificate template do not allow the current user to enroll for this type of certificate (0x80094012)

I think this must related to permissions however I am not sure how to proceed - what is the best practice to allow child domain administrators to request certificates from the subordinate CA located in the parent domain?

My inf file is below:

[NewRequest]
Subject="CN=svr1.other.mydom.local"
Exportable=TRUE
KeyLength=2048
KeySpec=1
MachineKeySet=TRUE
[EnhancedKeyUsageExtension]
OID=1.3.6.1.5.5.7.3.1 ; Server Authentication
OID=1.3.6.1.5.5.7.3.2 ; Client Authentication
[RequestAttributes]
CertificateTemplate = WebServer

and i am running the following commands on svr1.other.mydom.local as administrator@other.mydom.local below:

certreq -new c:\svr1.inf c:\svr1.req
certreq -submit c:\svr1.req c:\svr1.cer ; I get the error here

Is the user a member of a security group that has Read and Enroll permission on the certificate template? That is required.

Administering Certificate Templates
http://technet.microsoft.com/en-us/library/cc725621%28v=ws.10%29

When you install certificates into the computer store and use auto-enrollment or manually request the certificate using the Certificates snap-in, the requesting computer account needs Read and Enroll permissions on the certificate template.

However, when you're using Certreq.exe to request certificates, even if they are computer certificates and use MachineKeySet = True, the requesting user needs Read and Enroll permissions on the certificate template. When you use Certreq.exe, the computer permissions are not used.