NRPE 1.8 and Nagios 3.0.6

I have a remote host (AIX) which is configured and all checks working correctly with Nagios 2.7.
I have configured a new Nagios 3.0.6 server and this host shows all checks not working.
The remote host has NRPE v1.8. Is this not compatible with Nagios 3.0.6?
Do I need to update NRPE on the remote host.

TIA