To see all the data in the X and Y Linear Axes plot, try zooming in on the points in the lower left corner. Both plots include three points that have error bars.
The code that calculates the grid and labels for logarithmic axes is
based on David Harrison's C version in
One limitation of the logarithmic axis feature is that sometimes not enough grid lines are displayed because the range of values is small. This bug is present in the original C version of xgraph. However, since logarithmic axes are usually used to show data with large ranges, this bug usually only shows up when zooming in by hand.