snmp dynamic index on hp-unix found wrong index

[mhabdank]

I am trying to monitor disk free space via snmp on hp-ux 11iv2.
When i run:
[root@zabbix ~]# snmpwalk -v 2c -c public 10.5.255.10 HP-UNIX::fileSystemDir
HP-UNIX::fileSystemDir.1073741825.10 = STRING: "/stand"
HP-UNIX::fileSystemDir.1073741827.10 = STRING: "/"
HP-UNIX::fileSystemDir.1073741828.10 = STRING: "/tmp"
HP-UNIX::fileSystemDir.1073741829.10 = STRING: "/home"
...
[root@zabbix ~]# snmpget -v 2c -c public 10.5.255.10 HP-UNIX::fileSystemDir.1073741829.10
HP-UNIX::fileSystemDir.1073741829.10 = STRING: "/home"
[root@zabbix ~]# snmpget -v 2c -c public 10.5.255.10 HP-UNIX::fileSystemBlock.1073741829.10
HP-UNIX::fileSystemBlock.1073741829.10 = INTEGER: 16384

and when i tried to create item using snmp dynamic index query like this:
HP-UNIX::fileSystemBlock["index","HP-UNIX::fileSystemDir", "/home"]
item change status to not supported and error is logged:
Item [rx1dev:snmp_disk_size_stand] error: SNMP error [(noSuchName) There is no such variable name in this MIB.]

I'v changed debug level to 4 (log attached) and i saw that founded index is wrong:
27248:20110321:104659.469 FOUND: Index is 10

but in this query index is:
1073741829.10

and as a result dynamic index search doen't work as expected.

best regards

Mikolaj Habdank