SNMP::Util - set fails in script.

[JC]

I'm writing a Perl script that will set several MIB variables.
When I run the script I get the following error messages:

STORE(SNMP::MIB=HASH(0x996ce74) enterprises.9.9.96.1.1.1.1.14
HASH(0x9aadf08)) : write access to the MIB not implemented

snmpset 10.10.1.1 index 5 .1.3.6.1.4.1.9.9.96.1.1.1.1.14 6

set Bad variable type (Sub-id not found: (top) -> enterprises)

Here's a very short version of the script:
---------------------------
#!/usr/bin/perl

use SNMP::Util;

$h = "10.10.1.1";
$c = "private";
$oid=".1.3.6.1.4.1.9.9.96.1.1.1.1.14";
$ix = "5";
$value="6"; #destroy

$session = new SNMP::Util(-device => $h,
-community => $c,
-timeout => 2);
$session->set(index => $ix,$oid => $value)
---------------------------

If I change the OID to something like .1.3.6.1.2.1.2.2.7
(ifAdminStatus) along with an appropriate index, the script runs fine.
The problem I think might have something do to with the fact that the
OID's index does not exist until the set operation is performed.
However, there are no snmp packets (of any sort) sent when the script
fails - so I know it's not doing a get operation prior to the set.
(verified with Wireshark)

Any thoughts/ideas would be greatly appreciated.

Thanks
JC