This sounds like the default mount behavior is not allowing ACLs on the filesystem. getfacl will report the normal filesystem permissions without error, but setfacl is unable to operate because the filesystem is mounted without the ACL option.
You can add this in /etc/fstab or by modifying your filesystem options.
Assuming you have the /home filesystem on /dev/sda, you can do the following:
Modify Filesystem method:
sudo /sbin/tune2fs -o +acl /dev/sda
Modify /etc/fstab method:
/dev/sda /home ext3 defaults,acl 1 2
Using either method, the filesystem has to be remounted to take effect. You can accomplish this by rebooting, or by running
sudo /bin/mount -o remount /home