Applying new settings to texture gets :(NPOT)not yet compressed' message. Why?

I have doen t$$anonymous$$s many hundreds of time before and normally the texture size gets updated so I can see ow much space I've saved by compresing the texture or losing the mipmaps etc. However today for some reason the texture size message just reads 'not yet compressed'. I tried $$anonymous$$tting reimport and that did not$$anonymous$$ng.

WHats going on here? Any ideas?

AH, I justs discovered t$$anonymous$$s texture reads (NPOT).Non power of two.