Hyper-V can't ping parent and vice versa

I have a 64bit WS 2008 Ent Svr, and its running local hyper-v session (32bit WS 2003 Std). The hyper-v setting uses the external connection and can do everything just fine (RDC, ping network gear/servers, shares) However, I can't ping the parent server via IP or Name, nor can the parent see the local hyper-v session. I need help to resolve this issue.

David