Problem creating SNMP data query using cacti 8.8b

[pieterswartz]

Using bash on SLES11.2, the following snmpwalk execute perfectly:

(ydjdrman01:root)-(jobs:0)-(~)
(! 1015)-> snmpwalk -v2c -c jseitd 10.3.6.147 .1.3.6.1.4.1.2021.881.1.101
UCD-SNMP-MIB::ucdavis.881.1.101.1 = STRING: "mitslcsp2pool"
UCD-SNMP-MIB::ucdavis.881.1.101.2 = STRING: "mitslesp2pool"
UCD-SNMP-MIB::ucdavis.881.1.101.3 = STRING: "rpool"
UCD-SNMP-MIB::ucdavis.881.1.101.4 = STRING: "smspool"

However executing the same query in XML format:

+ Running data query [10].
+ Found type = '3' [SNMP Query].
+ Found data query XML file at '/usr/share/cacti/resource/snmp_queries/zpool_usage.xml'
+ XML file parsed ok.
+ <oid_num_indexes> missing in XML file, 'Index Count Changed' emulated by counting oid_index entries
+ Executing SNMP walk for list of indexes @ '.1.3.6.1.4.1.2021.881.1.101' Index Count: 0
+ No SNMP data returned

Here is the XML file:

<interface>
<name>Get ZFS zpool usage</name>
<description>Query Solaris host for available ZPools</description>
<oid_index>.1.3.6.1.4.1.2021.881.1.101</oid_index>
<index_order>ZpoolName</index_order>
<index_order_type>alphabetic</index_order_type>
<index_title_format>|chosen_order_field|</index_title_format>
<fields>
<ZpoolName>
<name>name</name>
<method>walk</method>
<source>value</source>
<direction>input</direction>
<oid>.1.3.6.1.4.1.2021.881.1.101</oid>
</ZpoolName>
<ZpoolDataUsage>
<name>usedbydata</name>
<method>walk</method>
<source>value</source>
<direction>output</direction>
<oid>.1.3.6.1.4.1.2021.881.4.101</oid>
</ZpoolDataUsage>
<ZpoolSnapshotUsage>
<name>usedbysnapshots</name>
<method>walk</method>
<source>value</source>
<direction>output</direction>
<oid>.1.3.6.1.4.1.2021.881.2.101</oid>
</ZpoolSnapshotUsage>
<ZpoolUsed>
<name>used</name>
<method>walk</method>
<source>value</source>
<direction>output</direction>
<oid>.1.3.6.1.4.1.2021.881.3.101</oid>
</ZpoolUsed>
<ZpoolAvailable>
<name>available</name>
<method>walk</method>
<source>value</source>
<direction>output</direction>
<oid>.1.3.6.1.4.1.2021.881.5.101</oid>
</ZpoolAvailable>
<ZpoolCapacity>
<name>Capacity</name>
<method>walk</method>
<source>value</source>
<direction>output</direction>
<oid>.1.3.6.1.4.1.2021.881.6.101</oid>
</ZpoolCapacity>
</fields>
</interface>

This data query works with cacti 8.7i but not with version 8.8b. What do I do wrong?