Problem with Cisco : "Undefined variable: snmp_readstring"

[lasylve]

I use mactrack 2.9-1 with latest versions of PA and cacti.

I can not get MAC adresses on Cisco devices while I get IP adresses resolution working fine. Moreover, mactrack is working like a charm with 3COM or Enterasys equipments.

When I perform a manual scan on a Cisco switch : "php mactrack_scanner.php -id=8 -d" I get the following error message for each VLAN on my Cisco switch :

Notice: Undefined variable: snmp_readstring in /usr/share/cacti/site/plugins/mactrack/lib/mactrack_cisco.php on line 136
Timeout: No Response from x.x.x.x:161.
DEBUG: VLAN Analysis for VLAN: 648/XXXXXX-48 is complete. ACTIVE PORTS: 0

Can someone help me ? I'm using snmp v2 or v3 on Cisco and both versions do not work. It would be really great if I could get MAC resolution working on Cisco devices.