I also tried my K10d, in normal mode only as it doesn't have live view.
It seems as the k10 also detects a pan and then only allow the SR to operate in vertical mode.
Notice the blur in the background, I'm panning sideways, but the blur on the tripodlegs are mostly vertical. Thus the SR is now only working in a vertical direction, as expected if there is a panning mode.
Here is the same thing shot with the K5, from live view.
Same story, panning sideways, blur on legs only vertical. Thus SR is locked sideways.
And finally, the K5 in normal mode.
The legs are also blurred sideways, really bad one might add. SR is not locked sideways even though I was panning.
I call it a bug. Unless someone can come up with a better explanation.
Anyhow, with the K5, turn off SR during a pan.
(for some reason exif is partially stripped by PS, but all pictures where marked as "stabilized")