Nagios 1.4.8 plugins not checking Solaris?

Hi! I am currently trying to perform a disk check on a Solaris 10 machine using the check_by_ssh plugin and calling the check_disk plugin on a Solaris 10 machine. I get the following error when running the plugin on a Solaris 10 machine:

Remote command execution failed: bash: /usr/local/nagios/libexec/check_disk: Invalid argument

However, the same check on a Red Hat machine returns the following:

DISK OK - free space: / 3647 MB (93% inode=98%); /boot 71 MB (76% inode=99%); /dev/shm 2025 MB (100% inode=99%); /srv 21697 MB (99% inode=99%); /usr 3059 MB (78% inode=92%); /var 27913 MB (99% inode=99%);| /=266MB;3710;3916;0;4123 /boot=22MB;88;93;0;98 /dev/shm=0MB;1822;1923;0;2025 /srv=76MB;20645;21792;0;22939 /usr=853MB;3709;3915;0;4122 /var=111MB;26572;28048;0;29525

My Question is how to get check_disk using check_by_ssh running on a solaris machine?