Version: 1.2.0_devel (using KDE 3.4.0, compiled sources) Compiler: gcc version 3.4.3 OS: SunOS (sun4u) release 5.8 Currently, autoscale sets axis min/max values to that of the curve they contain, rounded to the next "nice" value. When you have boolean values with a range 0 -> 1, he result is that you can't see much else than value changes as the rest is hidden by either the top axis or the bottom axis. The same applies to continuous variables which are clipped to some interval like [-10;10] for instance. It would certainly be very useful to add some margin so that all points of the curve are STRICTLY contained in the plottable area (that is, excluding the axes).
If you open the plot dialog, click on the Range tab, and click on the Auto Border radio option of the Y Axis group then I think your problem should be solved. For values ranging from 0 to 1 this will give a y-axis range from -0.025 to 1.025, which looks about right to me. If this doesn't "solve" your problem then please provide more details (perhaps include a screen shot of the plot and the settinsg you used to generate it).
Awaiting more information
Sorry, you are right, and it even seems to be the default. The user who showed me the problem was actually using an existing .kst, and he probably changed that setting at some point without noticing.