K5 White Balance Problems

I have noticed what seems to be a bug in my K5 software.

When shooting in the studio recently I noticed inconsistencies in the white balance between photos. I had the WB set to manual but the WB values that are showing up in Lightroom are all over the place.

For example I have 5 photos taken within a short 15 second burst and the WB values are:

5250
5150
6600
5100
5150

Anyone seen anything like this before?

It seems my problem has already been discussed here:

link