There known issues with Solaris 10, NFS v4 and
NetApps. AFAIK their haven't been patches from either Sun or NetApp
but here's one solution, inelegant though it may be:
###############
The easiest workaround is to force Solaris to use NFSv3 instead. You can
do this by uncommenting and changing the NFS_CLIENT_VERSMAX parameter in
/etc/default/nfs
###############