Target did not eval into defined data problem

Hello!

I have the following lines in my mrtg.cfg:

Target[eselivm3v80l_memory]:
.1.3.6.1.4.1.193.105.1.1.1.21.1.0&.1.3.6.1.4.1.193.105.1.1.1.21.1.0:public@eselivm3v80l:4000::::2
Title[eselivm3v80l_memory]: Memory usage of NETSim
MaxBytes[eselivm3v80l_memory]: 10000000
RouterUptime[eselivm3v80l_memory]: public@eselivm3v80l:4000
Options[eselivm3v80l_memory]: growright,nopercent,unknaszero
LegendI[eselivm3v80l_memory]: Memory usage of NETSim, as reported by the OS
LegendO[eselivm3v80l_memory]: Memory usage of NETSim, as reported by the OS
ShortLegend[eselivm3v80l_memory]: bytes
YLegend[eselivm3v80l_memory]: Bytes

I can get the necessary values via SNMP:

> snmpget -v2c -c public eselivm3v80l:4000 .1.3.6.1.4.1.193.105.1.1.1.21.1.0
NME-MIB::netsimVMTotalMemoryUsageByOS.0 = Counter64: 339832832 bytes
> snmpget -v2c -c public eselivm3v80l:4000 sysUpTime.0
DISMAN-EVENT-MIB::sysUpTimeInstance = Timeticks: (333907) 0:55:39.07

Still I get these errors from mrtg:

ERROR: Target[eselivm3v80l_memory][_IN_] ' $target->[34]{$mode} ' did
not eval into defined data
ERROR: Target[eselivm3v80l_memory][_OUT_] ' $target->[34]{$mode} ' did
not eval into defined data

Do you know why? I'm using mrtg-2.12.2 on SuSE 10 SP3.