Hello,
not sure if this qualifies as a bug or a feature request but it seems like an overlook to me so i figured bug? Anyway, when you clip the heightfield via Operatons\Heightfield\Clip Heightfield, there is no progress indicator. For larger maps this operation does make it look like something might have gone wrong... but you need simply wait for the toolbar icons to ungray and then you know its done. (well that and it resamples the mosaic for preparation to update the display)
-Mike