PowerConnect2824: cannot configure VLAN via SNMP

My task is to configure dynamically VLAN assignment for the switch ports.

All VLANs are created in the initial switch configuration. I am using OIDs from Q-BRIDGE-MIB: dot1qPvid, dot1qVlanStaticEgressPorts, dot1qVlanStaticUntaggedPorts to assign particular VLAN for particular port. Port PVID is set successfully like this for port 20 and VLAN 123:

$ snmpset -v2c -cprivate switch.lab .1.3.6.1.2.1.17.7.1.4.5.1.1.20 u 123

$ snmpget -v2c -cprivate switch.lab .1.3.6.1.2.1.17.7.1.4.5.1.1.20
SNMPv2-SMI::mib-2.17.7.1.4.5.1.1.20 = Gauge32: 123

dot1qVlanStaticEgressPorts and dot1qVlanStaticUntaggedPorts are updated for VLAN123 automatically:

$ snmpget -v2c -cprivate switch.lab .1.3.6.1.2.1.17.7.1.4.3.1.2.123
SNMPv2-SMI::mib-2.17.7.1.4.3.1.2.20 = Hex-STRING: 00 00 10 00 00 00 ...

$ snmpget -v2c -cprivate switch.lab .1.3.6.1.2.1.17.7.1.4.3.1.4.123
SNMPv2-SMI::mib-2.17.7.1.4.3.1.2.20 = Hex-STRING: 00 00 10 00 00 00 ...

But there is a problem with removing from dot1qVlanStaticEgressPorts and dot1qVlanStaticUntaggedPorts the VLAN that was there before:

$ snmpget -v2c -cprivate switch.lab .1.3.6.1.2.1.17.7.1.4.3.1.2.100
SNMPv2-SMI::mib-2.17.7.1.4.3.1.2.20 = Hex-STRING: FF FF 10 00 00 00 ...

$ snmpset -v2c -cprivate switch.lab .1.3.6.1.2.1.17.7.1.4.3.1.2.100 x 0xFFFF0000...
Error in packet.
Reason: (genError) A general failure occured
Failed object: SNMPv2-SMI::mib-2.17.7.1.4.3.1.2.100

According to tcpdump SNMP set sends the data exactly in the same format as it is returned by SNMP get.

Firmware: 1.0.0.44

Please advice.

P.S. I am using similar technology on other switches (Cisco, Linksys, SMC) without any problem.

Thanks