I am working on a network that is majority HP Comware switches running MST instance 0 for all VLANs. 

I have approx 12 Cisco switches also running in MST spanning-tree instance 0 configuration for all VLANs. 

The Root bridge on the Cisco switches are the HP Core, which is correct, as this has been configured as the Primary Root for all VLANs (Priority 0)

The problem I face, is that if a new Cisco switch configured with PVST connects to the network all my Cisco switches uplinks to the Core go offline. In the logs I see examples of the following:

SPANTREE-2-PVSTSIM_FAIL: Blocking root port Po1: Inconsistent Inferior PVST BPDU recived on VLAN 4, claiming root 32772:mac address

If the MST tree already has a Root for instance 0; why would the Cisco switch shutdown the interface when receiving an inferior BPDU. Should it no ignore this packet and maintain its current Root?

Any ideas, is it possible to turn off PVSTSIM somehow or another configuration to prevent this from occurring?