Several samples recently run on the SSPPS NMR spectrometers showed spectra that could only be explained by invoking strong coupling. Strong coupling is a distortion of the relative intensities of the lines in a multiplet due to the scalar coupling approaching the chemical shift difference. The lines in the multiplet closest to the coupled resonance increase in intensity, while the lines on the far side decrease. This makes the multiplet appear to "lean" towards its coupling partner. Some examples can be found on Hans Reich's pages at the University of Wisconsin1, and a very thorough description of strong coupling and its origin can be found in Neil Jacobsen's book2.
