I lost the URL to the bug tracker or I would have posted it there straight. This is not a major bug, and perhaps not even a minor bug and doesn't affect game play that much.
But it does look silly.
I accepted a contract for re-positioning a satellite. Turns out that the "new" orbit is so close to the current, that the contract got marked as "completed" while I was checking on that particular satellite in the first place (without doing anything). Easiest 80,000 Kerbucks ever!
Proposal: I'm not asking for 30° inclination changes or extreme apo/peri changes, but a contract for new orbit parameters should at least mean new orbit parameters to provide a challenge, and not (nearly) the same as existing ones.