Setting wrong resize options gives false error message about permissions

On the "Resize images" dialogue, I want to change the scale. So I type in a number--say "30." Then I click "Resize."

Resulting error message: "'[Name].JPG' cannot be resized. Check whether you have permission to write to this folder."

But the problem has nothing to do with permissions. Rather, though I wanted to change the "Scale" options, I didn't click the radio button for it. So the "Select a size" option was still selected. *That* was the actual error. When I reenter the desired percentage and click the "Scale" button, all works fine.

So we have a misleading error message.

Additionally (underlying the human error that led to the error message):

Expected behavior: When I enter a new value for "Scale," the selected option will automatically change to "Scale."
Actual behavior: It doesn't. The selected option remains "Select a size."

And a fine point: Ideally, the value entered in "Scale" would be sticky -- that is, the next time this dialogue box appears, it would retain the last-entered value.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: nautilus-image-converter 0.3.1~git20110416-0ubuntu1
ProcVersionSignature: Ubuntu 3.0.0-14.23-generic 3.0.9
Uname: Linux 3.0.0-14-generic x86_64
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Tue Dec 13 18:48:05 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: nautilus-image-converter
UpgradeStatus: Upgraded to oneiric on 2011-11-23 (20 days ago)