Henrik,

As you know, an active log backup will never expire.
The only way for the "35" day countdown to start, is to
inactivate the log backup. A log backup will only be inactivated
if there is no active database backup that requires that log
and then the INACTIVATELOGS command is run.
It sounds like this should be the case in your shop,
but apparently it is not.

There may be an active backup that exists that it is specifying
that is needs those logs to properly recover. That shouldn't normally
happen if you run weekly SELECTIVE backups and daily INCREMENTAL backups.
However, I have occasionally seen this happen when INCLUDE/EXCLUDE
lists were changed. The other possibility I can think of is
if the loggerid changed... and/or something is out of sync.
A few things to check more closely...
Are these log backups for a different logger id?
Are these log backups for a different NODENAME?
Are these log backups for a different Domino Server?

I would query all of your active backups for this Domino server,
to look at the backup dates. If all of the backup dates are
recent, then it is probably something else. You may find that
you have one database backup that is "holding" those logs
from expiring.

If you still can't get it resolved, please open a PMR with IBM.
A trace will identify what is causing this.
If you feel like looking at a trace yourself, add these options
to the INACTIVATELOGS command:
      /TRACEFILE=trace.txt /TRACEFLAGS=SERVICE

Thanks,

Del