I can't get standard curve calculations after log-transforming my X values. The unpaired Y values are dropped on the results table.

One user reported this problem when he tried to log-transform a value of 0 on his data table. Prism should just ignore that value--on which it cannot do the transform--and proceed normally otherwise. Removing the 0 works sometimes, but not every time. A strange bug that is fixed in Prism 4.

There is a work-around that will work every time and be easy to do. Go to the Results page. Click "Change Parameters" to bring back the Transform dialog. Check the box to transform Y and choose a do-nothing transform (for example, Y=K*Y, with K set to 1). Prism will "transform" all the Y values, including the unpaired ones, and this will ensure that they are carried over to the Results sheet.