[haasted]

Have you tried putting some deadlines on his tasks? Get him to commit to some deadlines for his tasks, obviously made with his input.

It's my experience that a lack of deadlines and a bit of interest from someone monitoring the progress, can lead to a state where a task seem unimportant. It's a bit weird, and I can only guess at what process is at play, but I have seen this effect in otherwise great developers.

[howcanisaythis]

We do essentially weekly sprints and he presents at the end of each week the progress made.

[ericHosick]

Just because you have weekly sprints doesn't mean the developer can't show their work more often (you just don't have the right as the PO to interrupt a developer).

I think at PivotalLabs, they have the PO's sitting near the developers.

Also, perhaps, during your iteration planning meetings, try and break the stories into tasks that feel like they are less than a day.

Also, listen more carefully during the daily standup/meeting. If the "what I am doing" is not one of the tasks or on the current log, maybe ask why. Whatever they are doing, add it to the tasks (if that really should be done).

If the answer to "what is inhibiting you" is "nothing" but the "less than" one day tasks are not complete then there is something inhibiting the developer(s). It is your job to make sure that whatever is causing the developer to fail meeting the commitments is fixed. Could be bad estimation on everyones part, could be that tasks feel overwhelming (as other people pointed out), could be the developer(s) are just not interested.

All of those are fixable.