Clustered Column Chart Axis Not Showing Data Points

I have a clustered column chart with week numbers on the x axis and a summed measure on the Y. For some reason the chart is not showing the smaller values (seems to be less than 100). I have tried playing with the Y axis start and end values but it does not really help. In addition, the X axis labels are not showing along the bottom even though I have them switched on (you should see week numbers 1 through 21).

So here's the chart when Y start and end values are left to auto (week 8 is missing) in fact no labels show:

Here I set the maximum Y value to be 100 and you now see the week 8 number appear:

Any ideas why I can't see X axis labels for any week number and why the Y axis won't scale to show smaller values?