Okay, a couple questions:
1) What have you named your project?
2) Is your project in the samples directory of the release?
The easiest way for you to troubleshoot this will be to understand how the builders work. Right-click on your project in the Package Explorer and choose Properties. Choose Builders from the list on the left. Select the "Import QCAR (Win)" builder and choose Edit...
First off, you will need to make sure that the project name used in the Working Directory and Arguments field matches the name of the project. For the ImageTargets sample, the Working Directory should be:
And the Arguments should be:
Replace "ImageTargets" in these two lines with the name of your project, should you rename it.
Now we can see that this builder executes the copyQCARLibs.bat file in the .externalToolBuilders directory. This directory is hidden, so you may need to set your file explorer to show hidden files and folders. the .externalToolBuilders folder is in the top level of the project. Open copyQCARLibs.bat with a text editor, and you can see what it is trying to do. It copies the following files:
..\..\build\lib\armeabi\libQCAR.so to libs\armeabi\
..\..\build\lib\armeabi-v7a\libQCAR.so to libs\armeabi-v7a\
The relative paths show you that this project is expected to be placed relative to the QCAR build directory. This builder will work from inside the samples folder, but you can modify it if you'd like to move the project elsewhere.
The purpose of this builder is to copy those libQCAR.so files to the libs folder. This is necessary, because every time you run ndk-build for your project all .so files are deleted from these directories.
I'm not yet sure why your build is breaking, but checking the project name and location are the first steps. Also try cleaning the project in Eclipse, just in case.