When updating exiting nodes feeds removes previously entered product dimensions

UC Feeds enters all of the Ubercart product data without error.

When updating an existing node by using nid as the 'unique target' in mapping and changing 'title' the result is the title is changed. But all three dimension field have been reset to 0 from previously entered data.

This is the CSV data that is being used for the update function.

title,nid
787878,1592

Dimensions: 22.22 mm × 11.11 mm × 10 mm as first entered
Dimensions: 0 mm × 0 mm × 0 mm after using the above CSV date for the update

i.e. diameter, thickness, hole are mapped to diameter, thickness, hole for this product entry.