Toner level detection problem via SNMP

I have a OKI MB290 printer, which shows at it's web page a toner level of 80%. However in Spiceworks it still keeps at 0% black toner remaining. It did already some rescans, but no success :-(

I did also already a snmpwalk (see attachment) and I think it gets the 80% from the printer via SNMP:

...
iso.3.6.1.2.1.43.11.1.1.6.1.1 = STRING: "toner"
iso.3.6.1.2.1.43.11.1.1.7.1.1 = INTEGER: 7
iso.3.6.1.2.1.43.11.1.1.8.1.1 = INTEGER: 141860
iso.3.6.1.2.1.43.11.1.1.9.1.1 = INTEGER: 80
iso.3.6.1.2.1.43.12.1.1.2.1.1 = INTEGER: 1
iso.3.6.1.2.1.43.12.1.1.3.1.1 = INTEGER: 3
iso.3.6.1.2.1.43.12.1.1.4.1.1 = STRING: "black"
...

Also the Spiceworks log tells me something about 80% toner:

...
Asset data for computer sagem
=============================
name: sagem
description: LF series printer
device_type: NetworkPrinter
ip_address: 192.168.123.11
last_boot_up_time:...