Can you upgrade to 10.1 and see if this issue persists? If it does, can you open a support ticket and include an SNMP walk of the device, you can do the following
Please download and install net-snmp from http://net-snmp.sourceforge.net/
You can download the Win32 binaries here: http://sourceforge.net/projects/net-snmp/files/net-snmp%20binaries/5.5-binaries/net-snmp-5.5.0-1.x86.exe/download
It doesn’t matter what machine do you install it on, as long as it reaches the device.
Run this command from “installation directory/bin/”: snmpwalk -v 2c -c public -O netU 127.0.0.1 1 > output.txt
(change the IP address and community string accordingly)
Pack the file output.txt into zip archive and send it.