using dump 0.4b41 (using libext2fs 1.39 of 29-May-2006) on centos 5

Just had a problem where running dump with the -n option but with no operator group on the system caused :

Adding the operator group or removing -n fixes the problem but it took a while to find.

Not current version (which I can't test) so is this a bug?

Cheers Mike