Refind having trouble "finding" Ubuntu

I have a mac mini i5 hd4600. Had 14.04 on an external USB drive.

Running out of space on internal drive, I cloned to a second USB drive, now the main mac drive.

Since then, refined doesn't recognize there is a linux install on previous USB drive. The drive is intact, Linux is on separate partition.

Any one else run into this? Any clues how I could resolve this?