Looks like 5661 is still reproducible

alex@localhost472:~/zabbix-2.0.4$ zabbix_agent -V
Zabbix agent v2.0.4 (revision 31984) (08 December 2012)
Compilation time: Dec 9 2012 22:02:52
alex@localhost472:~/zabbix-2.0.4$ sudo zabbix_agent -t vfs.dev.read[,operations]
vfs.dev.read[,operations] [u|788854]
alex@localhost472:~/zabbix-2.0.4$ sudo zabbix_agent -t vfs.dev.read[,ops]
vfs.dev.read[,ops] [m|ZBX_NOTSUPPORTED]
alex@localhost472:~/zabbix-2.0.4$ sudo zabbix_agent -t vfs.dev.read[,sps]
vfs.dev.read[,sps] [m|ZBX_NOTSUPPORTED]