[mrtg] ppp-trouble after upgrade (Debian lenny)

[Michael Frotscher]

Hello mrtg-users,

after upgrading my server to lenny I notice that the interaction of mrtg 
(2.16.2-3) and snmpd (5.4.1-12) is somewhat troublesome.

As the dialup-ppp-device keeps changing its snmp-target-id I long ago resolved 
to using the name to address the interface:

#ppp0@:public at localhost

As this worked before, it does not anymore, I get the error:

"did not eval into defined data"

Defining the target-id works, but as mentioned that changes with every dial-in 
and thus is not an option.

Does anyone experience the same? I'm not entirely sure whether the fault is 
with mrtg or with snmpd or lies within a compatibility issue between both.
-- 
Sincerely,
Michael