iTunes 12.1.0.50 - attempting to backup an iPad Air - IOS 8.2 fails

This is a continuing problem.

iTunes 12.1.0.50 - attempting to backup an iPad Air - IOS 8.2 - fails - displaying the following in an error pop-up:

"iPad <name> cannot be synced because there is not enough free space to hold all of the selected items (1MB needed 1,0618 MB available)"

At best, this is clearly a bogus error message (or Apple flunked 6th grade arithmetic) especially as iTunes itself shows 1.27GB Free.

Note: 12.1.0.50 is the latest iTunes provided by Apple/update. 12.1.1. is not provided by Apple update mechanisms. OSX 10.10.2 Security Update 215-003,

Feedback has been submitted -- again. (Submitted under both iTunes and iPad.)