I have never deployed using isc-dhcp. Do you have the console output?
Below is the console output for a successful Option43/60 deployment:
GOOD DHCP
v0.9.9-pre) started
Jan 1 00:00:31 udhcpc[2976]: send_discover: pkt num 0, secs 0
Jan 1 00:00:31 udhcpc[2976]: Sending discover...
[ 43.151015] Kernel watchdog refresh ended on core 1.
Jan 1 00:00:33 udhcpc[2976]: send_discover: pkt num 1, secs 512
Jan 1 00:00:33 udhcpc[2976]: Sending discover...
Jan 1 00:00:35 udhcpc[2976]: send_discover: pkt num 2, secs 1024
Jan 1 00:00:35 udhcpc[2976]: Sending discover...
Jan 1 00:00:37 udhcpc[2976]: No lease, forking to background.
Jan 1 00:00:57 udhcpc[3165]: send_discover: pkt num 0, secs 6656
Jan 1 00:00:57 udhcpc[3165]: Sending discover...
Jan 1 00:00:58 udhcpc[3165]: send_selecting: pkt num 0, secs 6912
Jan 1 00:00:58 udhcpc[3165]: Sending select for 10.220.85.147...
Jan 1 00:00:58 udhcpc[3165]: Lease of 10.220.85.147 obtained, lease time 259200
Jan 1 00:00:58 udhcpc[3165]: DHCP OPT 60 is not ArubaAP
Jan 1 00:00:58 udhcpc[3165]: DHCP OPT 60 is ArubaInstantAP
Jan 1 00:00:58 udhcpc[3165]: DHCP OPT 43, len: 43, buf: STORES:US:NY:8821,192.168.12.23,Aruba2example!
Jan 1 00:00:58 udhcpc[3165]: ams-ip: 192.168.22.23, length of ams-key: 11
Jan 1 00:00:58 udhcpc[3165]: DHCP OPT 42, len: 8, ip: 192.168.2.16
[ 70.059012] ip_time_handler: Got ip and packets on bond0 Started master election 35-0, rand 31
[ 79.423992] bonding: bond0: releasing backup interface eth1
[ 79.478381] ethernet_device_event: dev eth1 others: 9
[ 79.539550] ethernet_device_event: dev eth1 is down
[ 79.597063] ethernet_device_event: dev eth1 others: 8
[ 79.660543] ethernet_device_event: dev eth1 others: 13
[ 79.719150] ADDRCONF(NETDEV_UP): eth1: link is not ready
[ 79.782411] ethernet_device_event: dev eth1 is up
10.220.85.147 255.255.255.0 10.220.85.254
Compressing all files in the /etc/httpd directory...
Have you seen the Instant Validated Reference Design guide chapter "Aruba Instant management using Aruba AirWave"?